Fix S32A_D565_Opaque for RGBA on arm64

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

BUG=skia:2813
R=halcanary@google.com, djsollen@google.com, mtklein@google.com

Author: kevin.petit@arm.com

Review URL: https://codereview.chromium.org/458453002
1 file changed