configure: enable ffnvcodec, nvenc, nvdec for ppc6le

Adding the support to build FFMPEG with HW accelerated decode and encode on PPC64
little endian architecture.
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>

configure

@@ -6513,6 +6513,14 @@ if enabled x86; then
             disable ffnvcodec cuvid nvdec nvenc
             ;;
     esac
+elif enabled ppc64 && ! enabled bigendian; then
+    case $target_os in
+        linux)
+            ;;
+        *)
+            disable ffnvcodec cuvid nvdec nvenc
+            ;;
+    esac
 else
     disable ffnvcodec cuvid nvdec nvenc
 fi