drm/i915/mtl/gsc: query the GSC FW for its compatibility version

The compatibility version is queried via an MKHI command. Right now, the
only existing interface is 1.0
This is basically the interface version for the GSC FW, so the plan is
to use it as the main tracked version, including for the binary naming
in the fetch code.

v2: use define for the object size (Alan)

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230612181529.2222451-4-daniele.ceraolospurio@intel.com