drm/i915/adl_p: Enable modular fia

Alderlake P have modular FIA like TGL but it is always modular in all
skus, not like TGL that we had to read a register to check if it is
monolithic or modular.

BSpec: 55480
BSpec: 50572
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Clinton Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210514153711.2359617-11-matthew.d.roper@intel.com