drm/gt/guc: extract scheduler-related defines from guc_fwif.h

drm/gt/guc: extract scheduler-related defines from guc_fwif.h

Some upcoming KLVs are sized based on the engine counts, so we need
those defines to be moved to a separate file to include them from
guc_klv_abi.h (which is already included by guc_fwif.h).
Instead of moving just the engine-related defines, it is cleaner to
move all scheduler-related defines (i.e., everything engine or context
related). Note that the legacy GuC defines have not been moved and have
instead been dropped because Xe doesn't support any GuC old enough to
still use them.

While at it, struct guc_ctxt_registration_info has been moved to
guc_submit.c since it doesn't come from the GuC specs (we added it to
make things simpler in our code).

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patch.msgid.link/20251218223846.1146344-16-daniele.ceraolospurio@intel.com