drm/xe: add VM_BIND DECOMPRESS uapi flag

drm/xe: add VM_BIND DECOMPRESS uapi flag

Add a new VM_BIND flag, DRM_XE_VM_BIND_FLAG_DECOMPRESS, that lets userspace
express intent for the driver to perform on-device in-place decompression
for the GPU mapping created by a MAP bind operation.

This flag is used by subsequent driver changes to trigger scheduling of
GPU work that resolves compressed VRAM pages into an uncompressed PAT
VM mapping.

Behavior and semantics:
- Valid only for DRM_XE_VM_BIND_OP_MAP. IOCTLs using this flag on other ops
  are rejected (-EINVAL).
- The bind's pat_index must select the device "no-compression" PAT entry;
  otherwise the ioctl is rejected (-EINVAL).
- Only meaningful for VRAM-backed BOs on devices that support Flat CCS and
  the required hardware generation (driver will return -EOPNOTSUPP if not).
- On success the driver schedules a migrate/resolve and installs the
  returned dma_fence into the BO's kernel reservation
  (DMA_RESV_USAGE_KERNEL).

Compute PR: https://github.com/intel/compute-runtime/pull/898

v3: Rebase on latest drm-tip and add compute pr info

v2: Add kernel doc (Matt)

Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Mrozek, Michal <michal.mrozek@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Nitin Gote <nitin.r.gote@intel.com>
Acked-by: Michal Mrozek <michal.mrozek@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260304123758.3050386-6-nitin.r.gote@intel.com