drm/xe/dgfx: Release mmap mappings on rpm suspend

drm/xe/dgfx: Release mmap mappings on rpm suspend

Release all mmap mappings for all vram objects which are associated
with userfault such that, while pcie function in D3hot, any access
to memory mappings will raise a userfault.

Upon userfault, in order to access memory mappings, if graphics
function is in D3 then runtime resume of dgpu will be triggered to
transition to D0.

v2:
  - Avoid iomem check before bo migration check as bo can migrate
    to system memory (Matthew Auld)
v3:
  - Delete bo userfault link during bo destroy
  - Upon bo move (vram-smem), do bo userfault link deletion in
    xe_bo_move_notify instead of xe_bo_move (Thomas Hellström)
  - Grab lock in rpm hook while deleting bo userfault link (Matthew Auld)
v4:
  - Add kernel doc and wrap vram_userfault related
    stuff in the structure (Matthew Auld)
  - Get rpm wakeref before taking dma reserve lock (Matthew Auld)
  - In suspend path apply lock for entire list op
    including list iteration (Matthew Auld)
v5:
  - Use mutex lock instead of spin lock
v6:
  - Fix review comments (Matthew Auld)

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #For the xe_bo_move_notify() changes
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20240104130702.950078-1-badal.nilawar@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>