x86/synth_filter: remove the fma3 version ifdefs

This fixes compilation failures with --disable-fma3
Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavcodec/x86/dcadsp.asm

@@ -418,7 +418,5 @@ INIT_XMM sse2
 SYNTH_FILTER
 INIT_YMM avx
 SYNTH_FILTER
-%if HAVE_FMA3_EXTERNAL
 INIT_YMM fma3
 SYNTH_FILTER
-%endif

libavcodec/x86/dcadsp_init.c

@@ -82,9 +82,7 @@ SYNTH_FILTER_FUNC(sse)
 #endif
 SYNTH_FILTER_FUNC(sse2)
 SYNTH_FILTER_FUNC(avx)
-#if HAVE_FMA3_EXTERNAL
 SYNTH_FILTER_FUNC(fma3)
-#endif
 #endif /* HAVE_YASM */
 
 av_cold void ff_synth_filter_init_x86(SynthFilterContext *s)