x86: Add appropriate ifdefs around certain AVX functions.

nasm versions prior to 2.09 have trouble assembling some of our AVX code.
Protect these sections by preprocessor macros to allow compilation to pass.

libavcodec/x86/fft_mmx.asm

@@ -299,6 +299,7 @@ IF%1 mova  Z(1), m5
 
 INIT_YMM
 
+%ifdef HAVE_AVX
 align 16
 fft8_avx:
     mova      m0, Z(0)
@@ -387,6 +388,7 @@ fft32_interleave_avx:
     sub r2d, mmsize/4
     jg .deint_loop
     ret
+%endif
 
 INIT_XMM
 %define movdqa  movaps
@@ -532,6 +534,7 @@ DEFINE_ARGS z, w, n, o1, o3
 
 INIT_YMM
 
+%ifdef HAVE_AVX
 %macro INTERL_AVX 5
     vunpckhps      %3, %2, %1
     vunpcklps      %2, %2, %1
@@ -545,6 +548,7 @@ INIT_YMM
 
 DECL_PASS pass_avx, PASS_BIG 1
 DECL_PASS pass_interleave_avx, PASS_BIG 0
+%endif
 
 INIT_XMM
 
@@ -634,8 +638,10 @@ cglobal fft_dispatch%3%2, 2,5,8, z, nbits
     RET
 %endmacro ; DECL_FFT
 
+%ifdef HAVE_AVX
 DECL_FFT 6, _avx
 DECL_FFT 6, _avx, _interleave
+%endif
 DECL_FFT 5, _sse
 DECL_FFT 5, _sse, _interleave
 DECL_FFT 4, _3dn
@@ -847,4 +853,6 @@ DECL_IMDCT _sse, POSROTATESHUF
 
 INIT_YMM
 
+%ifdef HAVE_AVX
 DECL_IMDCT _avx, POSROTATESHUF_AVX
+%endif

libavcodec/x86/fft_sse.c

@@ -22,6 +22,7 @@
 #include "libavutil/x86_cpu.h"
 #include "libavcodec/dsputil.h"
 #include "fft.h"
+#include "config.h"
 
 DECLARE_ASM_CONST(16, int, ff_m1m1m1m1)[4] =
     { 1 << 31, 1 << 31, 1 << 31, 1 << 31 };
@@ -30,10 +31,12 @@ void ff_fft_dispatch_sse(FFTComplex *z, int nbits);
 void ff_fft_dispatch_interleave_sse(FFTComplex *z, int nbits);
 void ff_fft_dispatch_interleave_avx(FFTComplex *z, int nbits);
 
+#if HAVE_AVX
 void ff_fft_calc_avx(FFTContext *s, FFTComplex *z)
 {
     ff_fft_dispatch_interleave_avx(z, s->nbits);
 }
+#endif
 
 void ff_fft_calc_sse(FFTContext *s, FFTComplex *z)
 {