powerpc/ps3: fix ps3.h kernel-doc warnings

Fix some kernel-doc warnings in ps3.h:

- add @dev to struct ps3_dma_region
- don't mark a function as "struct"
- add Returns: description for one function
- add a short description for ps3_system_bus_set_drvdata()
- correct an enum @name
- move intervening "struct ps3_system_bus_device;" from between
  kernel-doc for ps3_dma_region_init() and the function declaration

to eliminate these warnings:

Warning: arch/powerpc/include/asm/ps3.h:96 struct member 'dev' not
 described in 'ps3_dma_region'
Warning: arch/powerpc/include/asm/ps3.h:118 struct ps3_system_bus_device;
 error: Cannot parse struct or union!
Warning: arch/powerpc/include/asm/ps3.h:166 int
 ps3_mmio_region_init(struct ps3_system_bus_device *dev, struct
 ps3_mmio_region *r, unsigned long bus_addr, unsigned long len, enum
 ps3_mmio_page_size page_size); error: Cannot parse struct or union!
Warning: arch/powerpc/include/asm/ps3.h:167 No description found for
 return value of 'ps3_mmio_region_init'
Warning: arch/powerpc/include/asm/ps3.h:407 missing initial short
 description on line:
 * ps3_system_bus_set_drvdata -
Warning: arch/powerpc/include/asm/ps3.h:473 Enum value
 'PS3_LPM_TB_TYPE_INTERNAL' not described in enum 'ps3_lpm_tb_type'
Warning: arch/powerpc/include/asm/ps3.h:473 Excess enum value
 '@PS3_LPM_RIGHTS_USE_TB' description in 'ps3_lpm_tb_type'

This leaves struct members in several structs and function parameters in
one function still undescribed.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20251129183636.1893634-1-rdunlap@infradead.org

arch/powerpc/include/asm/ps3.h

@@ -65,6 +65,7 @@ struct ps3_dma_region_ops;
 
 /**
  * struct ps3_dma_region - A per device dma state variables structure
+ * @dev: device structure
  * @did: The HV device id.
  * @page_size: The ioc pagesize.
  * @region_type: The HV region type.
@@ -108,15 +109,15 @@ struct ps3_dma_region_ops {
 		     dma_addr_t bus_addr,
 		     unsigned long len);
 };
+
+struct ps3_system_bus_device;
+
 /**
  * struct ps3_dma_region_init - Helper to initialize structure variables
  *
  * Helper to properly initialize variables prior to calling
  * ps3_system_bus_device_register.
  */
-
-struct ps3_system_bus_device;
-
 int ps3_dma_region_init(struct ps3_system_bus_device *dev,
 	struct ps3_dma_region *r, enum ps3_dma_page_size page_size,
 	enum ps3_dma_region_type region_type, void *addr, unsigned long len);
@@ -156,10 +157,12 @@ struct ps3_mmio_region_ops {
 	int (*free)(struct ps3_mmio_region *);
 };
 /**
- * struct ps3_mmio_region_init - Helper to initialize structure variables
+ * ps3_mmio_region_init - Helper to initialize structure variables
  *
  * Helper to properly initialize variables prior to calling
  * ps3_system_bus_device_register.
+ *
+ * Returns: %0 on success, %-errno on error (or BUG())
  */
 
 int ps3_mmio_region_init(struct ps3_system_bus_device *dev,
@@ -405,7 +408,7 @@ static inline struct ps3_system_bus_driver *
 }
 
 /**
- * ps3_system_bus_set_drvdata -
+ * ps3_system_bus_set_drvdata - set driver's private data for this device
  * @dev: device structure
  * @data: Data to set
  */
@@ -464,7 +467,7 @@ enum ps3_lpm_rights {
  * enum ps3_lpm_tb_type - Type of trace buffer lv1 should use.
  *
  * @PS3_LPM_TB_TYPE_NONE: Do not use a trace buffer.
- * @PS3_LPM_RIGHTS_USE_TB: Use the lv1 internal trace buffer.  Must have
+ * @PS3_LPM_TB_TYPE_INTERNAL: Use the lv1 internal trace buffer.  Must have
  *  rights @PS3_LPM_RIGHTS_USE_TB.
  */