ARM Skia NEON patches - 12 - S32_Blend

Blitrow32: S32_Blend fix and little speed improvement

- the results are now exactly similar as the C code
- the speed has improved, especially for small values of count

+-------+-----------+------------+
| count | Cortex-A9 | Cortex-A15 |
+-------+-----------+------------+
| 1     | +30%      | +18%       |
+-------+-----------+------------+
| 2     | 0         | 0          |
+-------+-----------+------------+
| 4     | - <1%     | +14%       |
+-------+-----------+------------+
| > 4   | -0.5..+5% | -0.5..+4%  |
+-------+-----------+------------+

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

BUG=skia:

Committed: http://code.google.com/p/skia/source/detail?r=13532

R=djsollen@google.com, mtklein@google.com

Author: kevin.petit@arm.com

Review URL: https://codereview.chromium.org/158973002

Change-Id: I75a4d2a31313664b4df057ea58821899646a1577
git-svn-id: http://skia.googlecode.com/svn/trunk@13543 2bbb7eff-a529-9590-31e7-b0007b416f81
ARM Skia NEON patches - 25 - S32A_D565_Opaque_Dither clean/bugfix/speed

BlitRow565: S32A_D565_Opaque_Dither: some improvements

    - Supports ARGB and ABGR
    - Less magic numbers
    - Reduced instruction count : 5-25% speedup
    - Fixed indentation, removed some commented and useless code

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

BUG=skia:
R=djsollen@google.com, mtklein@google.com

Author: kevin.petit@arm.com

Review URL: https://codereview.chromium.org/177963003

Change-Id: I4f6083372e653fda5224b0f74dc5affbaa4c8f8f
git-svn-id: http://skia.googlecode.com/svn/trunk@13577 2bbb7eff-a529-9590-31e7-b0007b416f81