drm/i915/pxp: Add MTL hw-plumbing enabling for KCR operation

Add MTL hw-plumbing enabling for KCR operation under PXP
which includes:

1. Updating 'pick-gt' to get the media tile for
KCR interrupt handling
2. Adding MTL's KCR registers for PXP operation
(init, status-checking, etc.).

While doing #2, lets create a separate registers header file for PXP
to be consistent with other i915 global subsystems.

Signed-off-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230511231738.1077674-3-alan.previn.teres.alexis@intel.com