[ARM] pxa: Add PXA support for PWM API

Patch mainly from Eric Miao, with minor edits by rmk.

Note: PWM0 and PWM2 share the same register I/O space and clock gating
on pxa{27x, 3xx}, thus PWM2 is treated in the driver as a child PWM of
PWM0. And this is also true for PWM1/3.

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/pxa3xx.c b/arch/arm/mach-pxa/pxa3xx.c
index 644550b..0f717df 100644
--- a/arch/arm/mach-pxa/pxa3xx.c
+++ b/arch/arm/mach-pxa/pxa3xx.c
@@ -239,6 +239,8 @@
 	PXA3xx_CKEN("SSPCLK", SSP2, 13000000, 0, &pxa27x_device_ssp2.dev),
 	PXA3xx_CKEN("SSPCLK", SSP3, 13000000, 0, &pxa27x_device_ssp3.dev),
 	PXA3xx_CKEN("SSPCLK", SSP4, 13000000, 0, &pxa3xx_device_ssp4.dev),
+	PXA3xx_CKEN("PWMCLK", PWM0, 13000000, 0, &pxa27x_device_pwm0.dev),
+	PXA3xx_CKEN("PWMCLK", PWM1, 13000000, 0, &pxa27x_device_pwm1.dev),
 
 	PXA3xx_CKEN("MMCCLK", MMC1, 19500000, 0, &pxa_device_mci.dev),
 	PXA3xx_CKEN("MMCCLK", MMC2, 19500000, 0, &pxa3xx_device_mci2.dev),
@@ -530,6 +532,8 @@
 	&pxa27x_device_ssp2,
 	&pxa27x_device_ssp3,
 	&pxa3xx_device_ssp4,
+	&pxa27x_device_pwm0,
+	&pxa27x_device_pwm1,
 };
 
 static struct sys_device pxa3xx_sysdev[] = {