This can be used for device register access from board code.
This allows access to capabilities in the RTC chip not abstracted in
U-Boot's RTC class. E.g., device NVRAM or a tamper detection circuit.
Cc: Klaus Goger <klaus.goger@theobroma-systems.com>
Cc: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>