drm/i915/fbc: update the impacted platforms in wa_22014263786

drm/i915/fbc: update the impacted platforms in wa_22014263786

wa_22014263786 is not applicable to the BMG and hence exclude it
from the wa.

v2: Limit this wa to display verion 11 to 14, drop DG2 from the
    exclusion list, use intel_display_wa (Lucas)

v3: simplify the wa handling loop (Jani)
    Description of wa moved to place where wa is applied (Ville)

v4: drop the platforms line from wa comments (Lucas)

Bspec: 74212, 66624
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20251007214317.875781-1-vinod.govindapillai@intel.com