powerpc: Fix kernel-doc comments in fsl_gtm.c

Fix some function names in kernel-doc comments.
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240408053109.96360-1-yang.lee@linux.alibaba.com

arch/powerpc/sysdev/fsl_gtm.c

@@ -77,7 +77,7 @@ struct gtm {
 static LIST_HEAD(gtms);
 
 /**
- * gtm_get_timer - request GTM timer to use it with the rest of GTM API
+ * gtm_get_timer16 - request GTM timer to use it with the rest of GTM API
  * Context:	non-IRQ
  *
  * This function reserves GTM timer for later use. It returns gtm_timer
@@ -110,7 +110,7 @@ struct gtm_timer *gtm_get_timer16(void)
 EXPORT_SYMBOL(gtm_get_timer16);
 
 /**
- * gtm_get_specific_timer - request specific GTM timer
+ * gtm_get_specific_timer16 - request specific GTM timer
  * @gtm:	specific GTM, pass here GTM's device_node->data
  * @timer:	specific timer number, Timer1 is 0.
  * Context:	non-IRQ
@@ -260,7 +260,7 @@ int gtm_set_timer16(struct gtm_timer *tmr, unsigned long usec, bool reload)
 EXPORT_SYMBOL(gtm_set_timer16);
 
 /**
- * gtm_set_exact_utimer16 - (re)set 16 bits timer
+ * gtm_set_exact_timer16 - (re)set 16 bits timer
  * @tmr:	pointer to the gtm_timer structure obtained from gtm_get_timer
  * @usec:	timer interval in microseconds
  * @reload:	if set, the timer will reset upon expiry rather than