[ARM] 4947/1: htc-egpio, a driver for GPIO/IRQ expanders with fixed input/output pins

implemented in CPLD chips on several HTC devices.

The original driver was written by Kevin O'Connor, I have adapted it to
use gpiolib and made the bus/register widths configurable.

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