Don't use __ARM_HAVE_NEON to detect NEON's presence in SkBlitter_RGB16

Don't use __ARM_HAVE_NEON to detect NEON's presence in SkBlitter_RGB16

Replace __ARM_HAVE_NEON by SK_ARM_NEON_IS_ALWAYS. It was the only
use of __ARM_HAVE_NEON apart from defining SK_ARM_NEON_IS_ALWAYS.

Signed-off-by: Kévin PETIT <kevin.petit@arm.com>;

BUG=skia:

Committed: http://code.google.com/p/skia/source/detail?r=13880

[djsollen, 2014-03-20 15:17:51]

lgtm

[kevin.petit, 2014-03-20 17:33:29]

The CQ bit was checked by kevin.petit@arm.com

[commit-bot: I haz the power, 2014-03-20 17:33:33]

CQ is trying da patch. Follow status at
https://skia-tree-status.appspot.com/cq/kevin.petit@arm.com/206543002/1

[commit-bot: I haz the power, 2014-03-20 18:37:12]

Change committed as 13880