drm/xe: Separate engine fuse handling into dedicated functions

The single function to handle fuse registers for all types of engines is becoming a bit long and hard to follow (and we haven't even added the compute engines yet). Let's split it into dedicated functions for each engine class.

Compute engine fusing is still not implemented; there appears to be some ambiguity in the bspec now, so we'll need to confirm the per-platform behavior with the hardware team first.

Signed-off-by: Matt Roper matthew.d.roper@intel.com