drm/xe/uapi: Fix documentation indentation

Fix these issues:

Documentation/gpu/driver-uapi:29: include/uapi/drm/xe_drm.h:817: WARNING:
+Bullet list ends without a blank line; unexpected unindent.
Documentation/gpu/driver-uapi:29: include/uapi/drm/xe_drm.h:835: WARNING:
+Definition list ends without a blank line; unexpected unindent.

Fixes: 75d3775 ("drm/xe/mmap: Add mmap support for PCI memory barrier")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/intel-xe/20250117164023.3fdc00b9@canb.auug.org.au/
Cc: Tejas Upadhyay <tejas.upadhyay@intel.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250117193827.91779-1-rodrigo.vivi@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: rodrigovivi

include/uapi/drm/xe_drm.h

@@ -814,29 +814,29 @@ struct drm_xe_gem_create {
  *
  * The @flags can be:
  *  - %DRM_XE_MMAP_OFFSET_FLAG_PCI_BARRIER - For user to query special offset
- *  for use in mmap ioctl. Writing to the returned mmap address will generate a
- *  PCI memory barrier with low overhead (avoiding IOCTL call as well as writing
- *  to VRAM which would also add overhead), acting like an MI_MEM_FENCE
- *  instruction.
+ *    for use in mmap ioctl. Writing to the returned mmap address will generate a
+ *    PCI memory barrier with low overhead (avoiding IOCTL call as well as writing
+ *    to VRAM which would also add overhead), acting like an MI_MEM_FENCE
+ *    instruction.
  *
- *  Note: The mmap size can be at most 4K, due to HW limitations. As a result
- *  this interface is only supported on CPU architectures that support 4K page
- *  size. The mmap_offset ioctl will detect this and gracefully return an
- *  error, where userspace is expected to have a different fallback method for
- *  triggering a barrier.
+ * Note: The mmap size can be at most 4K, due to HW limitations. As a result
+ * this interface is only supported on CPU architectures that support 4K page
+ * size. The mmap_offset ioctl will detect this and gracefully return an
+ * error, where userspace is expected to have a different fallback method for
+ * triggering a barrier.
  *
- *  Roughly the usage would be as follows:
+ * Roughly the usage would be as follows:
  *
- *  .. code-block:: C
+ * .. code-block:: C
  *
- *  struct drm_xe_gem_mmap_offset mmo = {
- *	.handle = 0, // must be set to 0
- *	.flags = DRM_XE_MMAP_OFFSET_FLAG_PCI_BARRIER,
- *  };
+ *     struct drm_xe_gem_mmap_offset mmo = {
+ *         .handle = 0, // must be set to 0
+ *         .flags = DRM_XE_MMAP_OFFSET_FLAG_PCI_BARRIER,
+ *     };
  *
- *  err = ioctl(fd, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo);
- *  map = mmap(NULL, size, PROT_WRITE, MAP_SHARED, fd, mmo.offset);
- *  map[i] = 0xdeadbeaf; // issue barrier
+ *     err = ioctl(fd, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo);
+ *     map = mmap(NULL, size, PROT_WRITE, MAP_SHARED, fd, mmo.offset);
+ *     map[i] = 0xdeadbeaf; // issue barrier
  */
 struct drm_xe_gem_mmap_offset {
 	/** @extensions: Pointer to the first extension struct, if any */