drm/xe: Fix kernel-doc comment syntax issues in header files

Fix doc comment formatting that does not conform to kernel-doc syntax
rules:

- xe_guc_relay_types.h: Add missing space after '/**' in member doc
  comment (/**@lock -> /** @lock)
- xe_oa_types.h: Fix struct documentation to use proper kernel-doc
  format (/** @xe_oa_buffer: -> /** struct xe_oa_buffer -)
- xe_pagefault_types.h: Use dash instead of colon as separator in
  struct doc (struct xe_pagefault_queue: -> struct xe_pagefault_queue -)
- xe_pt_walk.h: Use dash instead of colon as separator in function
  docs (xe_pt_num_entries: -> xe_pt_num_entries -,
  xe_pt_offset: -> xe_pt_offset -)

Assisted-by: GitHub Copilot:claude-sonnet-4.6
Reviewed-by: Brian Nguyen <brian3.nguyen@intel.com>
Link: https://patch.msgid.link/20260414225457.3687449-4-shuicheng.lin@intel.com
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>

drivers/gpu/drm/xe/xe_guc_relay_types.h

@@ -15,7 +15,7 @@
  * struct xe_guc_relay - Data used by the VF-PF Relay Communication over GuC.
  */
 struct xe_guc_relay {
-	/**@lock: protects all internal data. */
+	/** @lock: protects all internal data. */
 	spinlock_t lock;
 
 	/** @worker: dispatches incoming action messages. */

drivers/gpu/drm/xe/xe_oa_types.h

@@ -154,7 +154,9 @@ struct xe_oa {
 	u16 oa_unit_ids;
 };
 
-/** @xe_oa_buffer: State of the stream OA buffer */
+/**
+ * struct xe_oa_buffer - State of the stream OA buffer
+ */
 struct xe_oa_buffer {
 	/** @format: data format */
 	const struct xe_oa_format *format;

drivers/gpu/drm/xe/xe_pagefault_types.h

@@ -112,7 +112,7 @@ struct xe_pagefault {
 };
 
 /**
- * struct xe_pagefault_queue: Xe pagefault queue (consumer)
+ * struct xe_pagefault_queue - Xe pagefault queue (consumer)
  *
  * Used to capture all device page faults for deferred processing. Size this
  * queue to absorb the device’s worst-case number of outstanding faults.

drivers/gpu/drm/xe/xe_pt_walk.h

@@ -111,7 +111,7 @@ static inline bool xe_pt_covers(u64 addr, u64 end, unsigned int level,
 }
 
 /**
- * xe_pt_num_entries: Number of page-table entries of a given range at this
+ * xe_pt_num_entries - Number of page-table entries of a given range at this
  * level
  * @addr: Start address.
  * @end: End address.
@@ -132,7 +132,7 @@ xe_pt_num_entries(u64 addr, u64 end, unsigned int level,
 }
 
 /**
- * xe_pt_offset: Offset of the page-table entry for a given address.
+ * xe_pt_offset - Offset of the page-table entry for a given address.
  * @addr: The address.
  * @level: Page table level.
  * @walk: Walk info.