x86: superio: Add keyboard controller support to smsc_lpc47m driver

Add an api to enable and configure the integrated keyboard controller
on SMSC LPC47m superio chipset. It also adds several macros to help
future extension.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
3 files changed