mfd: max77620: Support Maxim 77663

Add support for Maxim 77663 using the Max77620 driver. The hardware
is very similar to Max77663/20024, although there are couple minor
differences.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>