mfd: db8500-prcmu: Fix multiple incorrectly documented function names

Fixes the following W=1 kernel build warning(s):

 drivers/mfd/db8500-prcmu.c:624: warning: expecting prototype for prcmu_get_current_mode(). Prototype was for prcmu_get_xp70_current_state() instead
 drivers/mfd/db8500-prcmu.c:908: warning: expecting prototype for db8500_set_ape_opp(). Prototype was for db8500_prcmu_set_ape_opp() instead
 drivers/mfd/db8500-prcmu.c:2303: warning: expecting prototype for db8500_prcmu_reset_modem(). Prototype was for db8500_prcmu_modem_reset() instead

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
Cc: Sundar Iyer <sundar.iyer@stericsson.com>
Cc: Mattias Nilsson <mattias.i.nilsson@stericsson.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/db8500-prcmu.c

@@ -616,7 +616,7 @@ enum romcode_read prcmu_get_rc_p2a(void)
 }
 
 /**
- * prcmu_get_current_mode - Return the current XP70 power mode
+ * prcmu_get_xp70_current_state - Return the current XP70 power mode
  * Returns: Returns the current AP(ARM) power mode: init,
  * apBoot, apExecute, apDeepSleep, apSleep, apIdle, apReset
  */
@@ -898,7 +898,7 @@ static void request_even_slower_clocks(bool enable)
 }
 
 /**
- * db8500_set_ape_opp - set the appropriate APE OPP
+ * db8500_prcmu_set_ape_opp - set the appropriate APE OPP
  * @opp: The new APE operating point to which transition is to be made
  * Returns: 0 on success, non-zero on failure
  *
@@ -2297,7 +2297,7 @@ u16 db8500_prcmu_get_reset_code(void)
 }
 
 /**
- * db8500_prcmu_reset_modem - ask the PRCMU to reset modem
+ * db8500_prcmu_modem_reset - ask the PRCMU to reset modem
  */
 void db8500_prcmu_modem_reset(void)
 {