drm/i915/dmc: Remove invalid PIPEDMC interrupt bits

drm/i915/dmc: Remove invalid PIPEDMC interrupt bits

On display version 35+ PIPEDMC_ATS_FAULT and
PIPEDMC_GTT_FAULT interrupt bits are no longer defined.

Update the interrupt mask to drop these.

Changes in v2:
- Move PIPEDMC_ERROR interrupt enable to a separate patch (Ville Syrjala)
Changes in v3:
- Add Bspec reference (Suraj Kandpal)
Changes in v4:
- Move bspec position in commit message(Suraj Kandpal)

Bspec: 70296
Signed-off-by: Dibin Moolakadan Subrahmanian <dibin.moolakadan.subrahmanian@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://patch.msgid.link/20260327064453.2241523-2-dibin.moolakadan.subrahmanian@intel.com