drm/i915/mtl: Add MTL forcewake support

MTL has separate forcewake tables for the primary/render GT and the
media GT; each GT's intel_uncore will use a separate forcewake table and
should only initialize the domains that are relevant to that GT.  The GT
ack register also moves to a new location of (GSI base + 0xDFC) on this
platform.

Note that although our uncore handlers take care of transparently
redirecting all register accesses in the media GT's GSI range to their
new offset at 0x380000, the forcewake ranges listed in the table should
use the final, post-translation offsets.

NOTE:  There are two ranges in the media IP that have multicast
registers where the two register instances reside in different power
wells (either VD0 or VD2).  We don't have an easy way to deal with this
today (and in fact we don't even access these register ranges in the
driver today), so for now we just mark those ranges as FORCEWAKE_ALL
which will cause all of the media power wells to be grabbed, ensuring
proper operation.  If we start reading/writing in those ranges in the
future, we can re-visit whether it's worth adding extra steering
complexity into our forcewake support.

Bspec: 67788, 67789, 52077
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Harish Chegondi <harish.chegondi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220910001631.1986601-1-matthew.d.roper@intel.com