[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 --cc arch/arm/mach-pxa/Kconfig
Simple merge

diff --cc arch/arm/mach-pxa/Makefile
Simple merge

diff --cc arch/arm/mach-pxa/devices.c
Simple merge

diff --cc arch/arm/mach-pxa/devices.h
Simple merge

diff --cc arch/arm/mach-pxa/pwm.c
Simple merge

diff --cc arch/arm/mach-pxa/pxa25x.c
Simple merge

diff --cc arch/arm/mach-pxa/pxa27x.c
Simple merge

diff --cc arch/arm/mach-pxa/pxa3xx.c
Simple merge