regmap: convert all regmap_update_bits() and co. macros to static inlines

There's no reason to have these as macros. Let's convert them all to
static inlines for better readability and stronger typing.

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20200615072313.11106-1-brgl@bgdev.pl
Signed-off-by: Mark Brown <broonie@kernel.org>