Fix compilation with old yasm that does not support AVX.

libswscale/x86/input.asm

@@ -304,8 +304,10 @@ RGB24_FUNCS 10, 12
 INIT_XMM ssse3
 RGB24_FUNCS 11, 13
 
+%if HAVE_AVX
 INIT_XMM avx
 RGB24_FUNCS 11, 13
+%endif
 
 ; %1 = nr. of XMM registers
 ; %2-5 = rgba, bgra, argb or abgr (in individual characters)
@@ -448,8 +450,10 @@ RGB32_FUNCS 0, 0
 INIT_XMM sse2
 RGB32_FUNCS 8, 12
 
+%if HAVE_AVX
 INIT_XMM avx
 RGB32_FUNCS 8, 12
+%endif
 
 ;-----------------------------------------------------------------------------
 ; YUYV/UYVY/NV12/NV21 packed pixel shuffling.
@@ -656,7 +660,7 @@ YUYV_TO_UV_FN 3, uyvy
 NVXX_TO_UV_FN 5, nv12
 NVXX_TO_UV_FN 5, nv21
 
-%ifdef HAVE_AVX
+%if HAVE_AVX
 INIT_XMM avx
 ; in theory, we could write a yuy2-to-y using vpand (i.e. AVX), but
 ; that's not faster in practice

libswscale/x86/output.asm

@@ -264,7 +264,7 @@ yuv2planeX_fn  9,  7, 5
 yuv2planeX_fn 10,  7, 5
 yuv2planeX_fn 16,  8, 5
 
-%ifdef HAVE_AVX
+%if HAVE_AVX
 INIT_XMM avx
 yuv2planeX_fn  8, 10, 7
 yuv2planeX_fn  9,  7, 5
@@ -404,7 +404,7 @@ yuv2plane1_fn 16, 6, 3
 INIT_XMM sse4
 yuv2plane1_fn 16, 5, 3
 
-%ifdef HAVE_AVX
+%if HAVE_AVX
 INIT_XMM avx
 yuv2plane1_fn  8, 5, 5
 yuv2plane1_fn  9, 5, 3