radeonsi: merge pm4 state and atom emit loops into one

radeonsi: merge pm4 state and atom emit loops into one

This merges both loops in si_draw by tracking which pm4 states are dirty
using the state atom mechanism used for other states. pm4 states now have
to set their own emit function.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24732>