regulator: pf8x00: Add suspend support

This patch adds suspend/resume support so that it is possible to
configure the LDOs and BUCKs as on or off during suspend phase as
well as to configure suspend specific voltages.

Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
Link: https://lore.kernel.org/r/4c2e79d4fa96befdc9a6c59c3ff27b0a34f9fb56.camel@googlemail.com


Signed-off-by: Mark Brown <broonie@kernel.org>