x86: gpio: Add GPIO driver for Intel ICH6 and later.

Implement <asm-generic/gpio.h> functions for Intel ICH6 and later.
Only GPIOs 0-31 are handled by this code.

Signed-off-by: Bill Richardson <wfrichar@chromium.org>

Signed-off-by: Simon Glass <sjg@chromium.org>
4 files changed