panfrost: Remove the standalone compiler

panfrost: Remove the standalone compiler

Now that the online compiler and pandecode are reliable and upstreamed,
nobody is using this. If somebody does need it, it should be easy enough
to bring back, I suppose. At the moment, it's just a maintenance hazard,
since meson is silly and does double builds for compiler updates (triple
for disassembler changes).

If people need the standalone _disassembler_, that can be added
trivially into pandecode (pandecode already includes the disassembler).

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Ryan Houdek <Sonicadvance1@gmail.com>