rockchip: Add option to prevent booting on power plug-in

rockchip: Add option to prevent booting on power plug-in

For Rockchip boards with the all rk8xx series PMICs (excluding the
rk808), it is sometimes desirable to not boot whenever the device is
plugged in. An example would be for the Odroid Go Advance.

This provides a configurable option to check the PMIC says it was
powered because of a plug-in event. If the value is 1 and this option
is selected, the device shuts down shortly after printing a message
to console stating the reason why it's shutting down. Powering up the
board with the power button is not affected.

This patch parallels the work done in the following patch series:
https://lore.kernel.org/u-boot/20220121133732.2397273-1-andre.przywara@arm.com/

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>