reset: Add reset_control_bulk API

Follow the clock and regulator subsystems' lead and add a bulk API
for reset controls.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210314154459.15375-5-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>