panfrost: implement SFBD raw format support on v4

For v4 GPUs, raw formats support is currently advertised as "not finished for SFBD". This patch implements it.

It fixes the issue mentioned in #10571. Unfortunately, I was not able to find thorough tests for this functionality (in particular, my tests with mpv, involving several streams with various pixel formats, always ended up with desc->block.bits=64). Please let me know if you have any suggestions.

Closes: #10571