drm/i915/xehp: Add compute workarounds

Additional workarounds are required once we start exposing CCS engines.

Note that we have a number of workarounds that update registers in the
shared render/compute reset domain.  Historically we've just added such
registers to the RCS engine's workaround list.  But going forward we
should be more careful to place such workarounds on a wa_list for an
engine that definitely exists and is not fused off (e.g., a platform
with no RCS would never apply the RCS wa_list).  We'll keep
rcs_engine_wa_init() focused on RCS-specific workarounds that only need
to be applied if the RCS engine is present.  A separate
general_render_compute_wa_init() function will be used to define
workarounds that touch registers in the shared render/compute reset
domain and that we need to apply regardless of what render and/or
compute engines actually exist.  Any workarounds defined in this new
function will internally be added to the first present RCS or CCS
engine's workaround list to ensure they get applied (and only get
applied once rather than being needlessly re-applied several times).

Co-author: Srinivasan Shanmugam
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220301231549.1817978-13-matthew.d.roper@intel.com