superio/common/conf_mode: Provide another common pnp entry/exit

ITE Super I/O's make use of this method to enter and exit in and out of
their PNP configuration. Provide functions for use in ram stage
component.

Change-Id: I2b546c2b17eefc89aaab4982192f5e9a15a16c2f
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5666
Tested-by: build bot (Jenkins)
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>
2 files changed