x86/proresdsp-init: add forgotten HAVE_YASM

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/x86/proresdsp-init.c

@@ -31,7 +31,7 @@ void ff_prores_idct_put_10_avx (uint16_t *dst, int linesize,
 
 void ff_proresdsp_x86_init(ProresDSPContext *dsp)
 {
-#if ARCH_X86_64
+#if ARCH_X86_64 && HAVE_YASM
     int flags = av_get_cpu_flags();
 
     if (flags & AV_CPU_FLAG_SSE2) {