drm/i915: Fix pipeDMC and ATS fault handling

drm/i915: Fix pipeDMC and ATS fault handling

The fault handler is supposed to return true when it
handles the fault. The pipeDMC and ATS handlers are
returning false instead which results in the
"unreported faults" WARN triggering when it shouldn't.

Fixes: f13011a79999 ("drm/i915: Pimp display fault reporting")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250224173017.29500-1-ville.syrjala@linux.intel.com
Reviewed-by: Vinod Govindapillai <vinod.govindapillai@intel.com>