drm/xe/sysctrl: Add system controller interrupt handler

drm/xe/sysctrl: Add system controller interrupt handler

Add system controller interrupt handler which is denoted by 11th bit in
GFX master interrupt register. While at it, add worker for scheduling
system controller work.

Co-developed-by: Soham Purkait <soham.purkait@intel.com>
Signed-off-by: Soham Purkait <soham.purkait@intel.com>
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Mallesh Koujalagi <mallesh.koujalagi@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Link: https://patch.msgid.link/20260428054826.1202076-2-raag.jadav@intel.com
Signed-off-by: Riana Tauro <riana.tauro@intel.com>