cmake: Add support for PNG_ARM_NEON_OPT NDK-r19
On Android, here is clang compiler change for
NDKs after ndk-r17c where the compiler intrinsics
for libpng are not part of the compiler for the
armeabi-v7a targets.
Add the supported png functions for these compiler
intrinsics, explicitly for 32-bit ARM builds.
Affects:
dEQP-VK.*
Components: Vulkan, Framework
VK-GL-CTS issue: 1638
Change-Id: Ib832f983294f5dd747720ed4a79a21e29a06f776
(cherry picked from commit
99a88af740c425bf250ce9cb2143aa6be3a778f2)