regulator: pwm-regulator: Demote kerneldoc header to standard comment

This particular comment doesn't have anything to do with documenting
functions or data structures. Instead it is used as a section header.

Fixes W=1 warning:

drivers/regulator/pwm-regulator.c:55: warning: Function parameter or member 'rdev' not described in 'pwm_regulator_init_state'

Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/pwm-regulator.c

···
 	unsigned int dutycycle;
 };
 
-/**
+/*
  * Voltage table call-backs
  */
 static void pwm_regulator_init_state(struct regulator_dev *rdev)