panfrost: Implement missing texture formats

 - Implements RGB565/RGBA5551 formats
 - Don't advertise support for flipped RGBA5551 and ETC

Fixes remaining tests in dEQP-GLES2.functional.texture.format.* which is
now at 36/36.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
2 files changed