drm/i915/gt: Also check set bits in clr_set()

When checking if the workarounds were applied successfully, the
read-back mask should also contain the bits being set: it's possible
that in a call to wa_write_clr_set(), the cleared bits are not a
superset of the set bits.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230630203509.1635216-8-lucas.demarchi@intel.com