Remove ifdefs for neon in row_neon*.cc

ifdefs on a function level are not needed for neon functions, unless
they are conditionally enabled in row.h.  No functions are conditionally
enabled at this time, so all ifdefs can be removed from row_neon.cc and
row_neon64.cc

TBR=kjellander@chromium.org
BUG=libyuv:599

Review URL: https://codereview.chromium.org/2044223002 .

source/row_neon.cc

@@ -2583,8 +2583,6 @@ void ARGBColorMatrixRow_NEON(const uint8* src_argb, uint8* dst_argb,
   );
 }
 
-// TODO(fbarchard): fix vqshrun in ARGBMultiplyRow_NEON and reenable.
-#ifdef HAS_ARGBMULTIPLYROW_NEON
 // Multiply 2 rows of ARGB pixels together, 8 pixels at a time.
 void ARGBMultiplyRow_NEON(const uint8* src_argb0, const uint8* src_argb1,
                           uint8* dst_argb, int width) {
@@ -2616,7 +2614,6 @@ void ARGBMultiplyRow_NEON(const uint8* src_argb0, const uint8* src_argb1,
   : "cc", "memory", "q0", "q1", "q2", "q3"
   );
 }
-#endif  // HAS_ARGBMULTIPLYROW_NEON
 
 // Add 2 rows of ARGB pixels together, 8 pixels at a time.
 void ARGBAddRow_NEON(const uint8* src_argb0, const uint8* src_argb1,