[ARM] 4964/1: htc-pasic3: MFD driver for PASIC3 LED control + DS1WM chip

This driver will provide registers, clocks and GPIOs of
the HTC PASIC3 (AIC3) and PASIC2 (AIC2) chips to the
ds1wm and leds-pasic3 drivers.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>