leds: simple driver for pwm driven LEDs

Add a simple driver for pwm driver LEDs.  pwm_id and period can be defined
in board file.  It is developed for pxa, however it is probably generic
enough to be used on other platforms with pwm.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 4157e86..584a3f6 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -24,6 +24,7 @@
 obj-$(CONFIG_LEDS_PCA955X)		+= leds-pca955x.o
 obj-$(CONFIG_LEDS_DA903X)		+= leds-da903x.o
 obj-$(CONFIG_LEDS_WM8350)		+= leds-wm8350.o
+obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o