drm/i915/mtl: Disable stolen memory backed FB for A0

drm/i915/mtl: Disable stolen memory backed FB for A0

Stolen memory is not usable for MTL A0 stepping beyond
certain access size and we have no control over userspace
access size of /dev/fb which can be backed by stolen memory.
So disable stolen memory backed fb by setting i915->dsm.usable_size
to zero.

v2: remove hsdes reference and fix commit message(Andi)
v3: use revid as we want to target SOC stepping(Radhakrishna)

Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230404181342.23362-1-nirmoy.das@intel.com