regulator: Remove unnecessary include of linux/delay.h from regulator drivers

All the drivers that need delay for the regulator voltage output voltage to
stabilize after being enabled or after being set to a new value has been
converted to implement enable_time and set_voltage_time_sel callbacks.
Then regulator core will take care of the necessary delay.

This patch removes the unneeded include of linux/delay.h in regulator drivers.

Signed-off-by: Axel Lin <[e-mail]>
Cc: Daniel Jeong <[e-mail]>
Cc: Sangbeom Kim <[e-mail]>
Cc: Chiwoong Byun <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/lp8755.c

···
 #include <linux/interrupt.h>
 #include <linux/gpio.h>
 #include <linux/regmap.h>
-#include <linux/delay.h>
 #include <linux/uaccess.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>

drivers/regulator/max77686.c

···
 
 #include <linux/kernel.h>
 #include <linux/bug.h>
-#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>

drivers/regulator/s2mps11.c

···
  */
 
 #include <linux/bug.h>
-#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>