regulator: mpq7920: Convert to use .probe_new

Use the new .probe_new instead.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20200114124449.28408-2-axel.lin@ingics.com


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