- On LE machines, A8B8G8R8_*_PACK32 are the same as R8G8B8A8
- Add support for B8G8R8A8_SRGB in various places

Bug: b/118386749
Test: dEQP-VK.renderpass.*
Change-Id: I16d587b72317a05277fe2c8b337af5670eb51310
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/29228Tested-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>