configure: rename cuda to ffnvcodec

Right now, if someone configures ffmpeg with for example --enable-nvenc they will
get an error message complaining about missing cuda.
This is very confusing and already has lead people into installing the CUDA SDK,
even though it's not what they need.

This will make it complain about ffnvcodec instead.
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>

configure

@@ -307,11 +307,11 @@ External library support:
   The following libraries provide various hardware acceleration features:
   --disable-amf            disable AMF video encoding code [autodetect]
   --disable-audiotoolbox   disable Apple AudioToolbox code [autodetect]
-  --disable-cuda           disable dynamically linked Nvidia CUDA code [autodetect]
   --enable-cuda-sdk        enable CUDA features that require the CUDA SDK [no]
   --disable-cuvid          disable Nvidia CUVID support [autodetect]
   --disable-d3d11va        disable Microsoft Direct3D 11 video acceleration code [autodetect]
   --disable-dxva2          disable Microsoft DirectX 9 video acceleration code [autodetect]
+  --disable-ffnvcodec      disable dynamically linked Nvidia code [autodetect]
   --enable-libdrm          enable DRM code (Linux) [no]
   --enable-libmfx          enable Intel MediaSDK (AKA Quick Sync Video) code via libmfx [no]
   --enable-libnpp          enable Nvidia Performance Primitives-based code [no]
@@ -1660,6 +1660,7 @@ HWACCEL_AUTODETECT_LIBRARY_LIST="
     cuvid
     d3d11va
     dxva2
+    ffnvcodec
     nvdec
     nvenc
     vaapi
@@ -2675,11 +2676,12 @@ zmbv_encoder_deps="zlib"
 
 # hardware accelerators
 crystalhd_deps="libcrystalhd_libcrystalhd_if_h"
-cuda_deps_any="libdl LoadLibrary"
-cuvid_deps="cuda"
+cuda_deps="ffnvcodec"
+cuvid_deps="ffnvcodec"
 d3d11va_deps="dxva_h ID3D11VideoDecoder ID3D11VideoContext"
 dxva2_deps="dxva2api_h DXVA2_ConfigPictureDecode ole32 user32"
-nvdec_deps="cuda"
+ffnvcodec_deps_any="libdl LoadLibrary"
+nvdec_deps="ffnvcodec"
 videotoolbox_hwaccel_deps="videotoolbox pthreads"
 videotoolbox_hwaccel_extralibs="-framework QuartzCore"
 xvmc_deps="X11_extensions_XvMClib_h"
@@ -2797,13 +2799,13 @@ qsvvpp_select="qsv"
 vaapi_encode_deps="vaapi"
 v4l2_m2m_deps_any="linux_videodev2_h"
 
-hwupload_cuda_filter_deps="cuda"
-scale_npp_filter_deps="cuda libnpp"
+hwupload_cuda_filter_deps="ffnvcodec"
+scale_npp_filter_deps="ffnvcodec libnpp"
 scale_cuda_filter_deps="cuda_sdk"
 thumbnail_cuda_filter_deps="cuda_sdk"
 
 amf_deps_any="libdl LoadLibrary"
-nvenc_deps="cuda"
+nvenc_deps="ffnvcodec"
 nvenc_deps_any="libdl LoadLibrary"
 nvenc_encoder_deps="nvenc"
 
@@ -3357,7 +3359,7 @@ avformat_deps="avcodec avutil"
 avformat_suggest="libm network zlib"
 avresample_deps="avutil"
 avresample_suggest="libm"
-avutil_suggest="clock_gettime cuda libm libdrm libmfx opencl user32 vaapi videotoolbox corefoundation corevideo coremedia wincrypt"
+avutil_suggest="clock_gettime ffnvcodec libm libdrm libmfx opencl user32 vaapi videotoolbox corefoundation corevideo coremedia wincrypt"
 postproc_deps="avutil gpl"
 postproc_suggest="libm"
 swresample_deps="avutil"
@@ -5811,8 +5813,10 @@ check_type "va/va.h va/va_enc_vp9.h"  "VAEncPictureParameterBufferVP9"
 
 check_type "vdpau/vdpau.h" "VdpPictureInfoHEVC"
 
-check_pkg_config cuda "ffnvcodec >= 8.0.14.1" \
+if ! disabled ffnvcodec; then
+    check_pkg_config ffnvcodec "ffnvcodec >= 8.0.14.1" \
         "ffnvcodec/nvEncodeAPI.h ffnvcodec/dynlink_cuda.h ffnvcodec/dynlink_cuviddec.h ffnvcodec/dynlink_nvcuvid.h" ""
+fi
 
 check_cpp_condition windows.h "!WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)" && enable winrt || disable winrt
 
@@ -6257,13 +6261,15 @@ if enabled x86; then
         mingw32*|mingw64*|win32|win64|linux|cygwin*)
             ;;
         *)
-            disable cuda cuvid nvdec nvenc
+            disable ffnvcodec cuvid nvdec nvenc
             ;;
     esac
 else
-    disable cuda cuvid nvdec nvenc
+    disable ffnvcodec cuvid nvdec nvenc
 fi
 
+enabled ffnvcodec && enable cuda
+
 enabled nvenc &&
     check_cc -I$source_path <<EOF || disable nvenc
 #include <ffnvcodec/nvEncodeAPI.h>