[ARM] pxa: make zylonite use the generic PWM backlight driver

Patch mostly by Eric Miao, minor edits by rmk.

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-pxa/zylonite_pxa300.c b/arch/arm/mach-pxa/zylonite_pxa300.c
index 324fb9d..6f7ae97 100644
--- a/arch/arm/mach-pxa/zylonite_pxa300.c
+++ b/arch/arm/mach-pxa/zylonite_pxa300.c
@@ -50,6 +50,7 @@
 	GPIO75_LCD_BIAS,
 	GPIO76_LCD_VSYNC,
 	GPIO127_LCD_CS_N,
+	GPIO20_PWM3_OUT,	/* backlight */
 
 	/* BTUART */
 	GPIO111_UART2_RTS,
@@ -200,9 +201,6 @@
 		/* detect LCD panel */
 		zylonite_detect_lcd_panel();
 
-		/* GPIO pin assignment */
-		gpio_backlight = mfp_to_gpio(MFP_PIN_GPIO20);
-
 		/* MMC card detect & write protect for controller 0 */
 		zylonite_mmc_slot[0].gpio_cd  = EXT_GPIO(0);
 		zylonite_mmc_slot[0].gpio_wp  = EXT_GPIO(2);