kestrel/leds/trigger: implement led trigger driver for group pwm

pca9633 i2c leds driver supports group pwm which currently not utilized
by leds-pca963x driver.
This patch exposes various registers values via sysfs to user and can be
used to achieve group blinking and dimming.

Signed-off-by: Amitesh Singh <[email protected]>

Author: amiteshsingh-cpi

drivers/leds/trigger/Kconfig

@@ -19,6 +19,14 @@ config LEDS_TRIGGER_TIMER
 
 	  If unsure, say Y.
 
+config LEDS_TRIGGER_GRPPWM
+	tristate "LED Group PWM trigger"
+	help
+	  This allows LEDs to be controlled by group pwm feature,
+          supported by pca9633 i2c driver
+
+          if unsure, say Y.
+
 config LEDS_TRIGGER_ONESHOT
 	tristate "LED One-shot Trigger"
 	help

drivers/leds/trigger/Makefile

@@ -16,3 +16,4 @@ obj-$(CONFIG_LEDS_TRIGGER_NETDEV)	+= ledtrig-netdev.o
 obj-$(CONFIG_LEDS_TRIGGER_PATTERN)	+= ledtrig-pattern.o
 obj-$(CONFIG_LEDS_TRIGGER_AUDIO)	+= ledtrig-audio.o
 obj-$(CONFIG_LEDS_TRIGGER_TTY)		+= ledtrig-tty.o
+obj-$(CONFIG_LEDS_TRIGGER_GRPPWM		+= ledtrig-grppwm.o