mfd: lpc_ich: Remove lpc_ich_cfg struct use

Future chipsets will use different register layouts that don't map
cleanly to the lpc_ich_cfg fields.  Remove the lpc_ich_cfg struct and
add explicit fields to the higher level lpc_ich_priv structure.

This change should have no functional impact.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Tested-by: Rajat Jain <rajatjain@juniper.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>