drm/i915: Move/adjust register definitions related to Wa_22011450934

drm/i915: Move/adjust register definitions related to Wa_22011450934

The implementation of Wa_22011450934 introduced three new register
definitions in i915_reg.h that didn't get moved to the GT/engine
register headers when all the other registers moved; let's move them to
the appropriate headers and tidy up their definitions now for
consistency:

 - STATE_ACK_DEBUG is moved to the engine register header and converted
   to a parameterized definition; the workaround only needs the RCS
   instance to be programmed, but there are instances on other engines
   that could be used by other workarounds in the future.

 - The two CULLBIT registers move to the GT register header.  Since
   they belong to MMIO ranges that became MCR starting with Xe_HP,
   their definitions should be defined as MCR_REG() and use an Xe_HP
   prefix to keep the register semantics clear.

Note that the MCR definition is just for consistency and to prevent
accidental misuse if other workarounds related to these registers show
up in the future.  There's no functional change to today's driver since
the workaround that references these registers only accesses them via
MI_LRR engine instructions.  Engine-initiated register accesses do not
utilize the same steering controls as CPU-initiated accesses; they
use a different steering control register (0x20CC) which is initialized
to a non-terminated DSS target by pre-OS firmware and never changed
thereafter (i915 does not touch it and userspace does not have
permission to change that register).

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230117202627.4134579-1-matthew.d.roper@intel.com