genirq/irqreturn: Fix kernel-doc warnings

irqreturn.h:6: warning: missing initial short description on line:
 * enum irqreturn
irqreturn.h:15: warning: Enum value 'IRQ_NONE' not described in enum 'irqreturn'
irqreturn.h:15: warning: Enum value 'IRQ_HANDLED' not described in enum 'irqreturn'
irqreturn.h:15: warning: Enum value 'IRQ_WAKE_THREAD' not described in enum 'irqreturn'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221124063013.28479-1-rdunlap@infradead.org

include/linux/irqreturn.h

@@ -3,10 +3,10 @@
 #define _LINUX_IRQRETURN_H
 
 /**
- * enum irqreturn
- * @IRQ_NONE		interrupt was not from this device or was not handled
- * @IRQ_HANDLED		interrupt was handled by this device
- * @IRQ_WAKE_THREAD	handler requests to wake the handler thread
+ * enum irqreturn - irqreturn type values
+ * @IRQ_NONE:		interrupt was not from this device or was not handled
+ * @IRQ_HANDLED:	interrupt was handled by this device
+ * @IRQ_WAKE_THREAD:	handler requests to wake the handler thread
  */
 enum irqreturn {
 	IRQ_NONE		= (0 << 0),