drm/xe: Add forcewake status to powergate_info

drm/xe: Add forcewake status to powergate_info

Dump forcewake status and ref counts for all domains as part
of this debugfs. This is the sample output from gt1-

$ cat /sys/kernel/debug/dri//0/gt1/powergate_info
Media Power Gating Enabled: yes
Media Slice0 Power Gate Status: down
GSC Power Gate Status: down
GT.ref_count=0, GT.forcewake=0x10000
VDBox0.ref_count=0, VDBox0.forcewake=0x10000
VEBox0.ref_count=0, VEBox0.forcewake=0x10000
GSC.ref_count=0, GSC.forcewake=0x10000

v2: Fix checkpatch issues

Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Signed-off-by: Vinay Belgaumkar<vinay.belgaumkar@intel.com>
Link: https://patch.msgid.link/20260204190314.2904009-3-vinay.belgaumkar@intel.com