mfd: regulator: clk: Split rohm-bd718x7.h

Split the bd718x7.h to ROHM common and bd718x7 specific parts
so that we do not need to add same things in every new ROHM
PMIC header. Please note that this change requires changes also
in bd718x7 sub-device drivers for regulators and clk.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>