uboot-imx

x86: baytrail: acpi: Add APIs for determining/clearing sleep state

This adds APIs for determining previous sleep state from ACPI I/O
registers, as well as clearing sleep state on BayTrail SoC.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>