Don't set -mno-avx

There is no point in intentionally disabling this feature; it
isn't enabled by default by the compiler - and if it were to be
enabled by default (if the toolchain baseline includes it, because
it can be expected to be supported everywhere) there would be no
reason to disable it.

Change-Id: I67019eea63c4fb7183d9e47cf16bc8485022fef2
diff --git a/decoder.x86_64.mk b/decoder.x86_64.mk
index b265f4f..4d926ec 100644
--- a/decoder.x86_64.mk
+++ b/decoder.x86_64.mk
@@ -1,4 +1,4 @@
-libavcd_cflags_x86_64 += -DX86 -msse4.2 -mno-avx  -DDEFAULT_ARCH=D_ARCH_X86_SSE42
+libavcd_cflags_x86_64 += -DX86 -msse4.2 -DDEFAULT_ARCH=D_ARCH_X86_SSE42
 
 libavcd_inc_dir_x86_64   +=  $(LOCAL_PATH)/decoder/x86
 libavcd_inc_dir_x86_64   +=  $(LOCAL_PATH)/common/x86