drm/i915: Add workaround numbers to GEN7_COMMON_SLICE_CHICKEN1 whitelisting

Those two workarounds needs to be implemented in UMD, KMD only needs
to whitelist the registers, so here only adding the workaround number
to facilitate future workaroud table checks.

Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211119140931.32791-2-jose.souza@intel.com