regulator: pca9450: Convert to use module_i2c_driver

Use module_i2c_driver to simplify driver init boilerplate.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/20200725014414.1825183-1-axel.lin@ingics.com


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