power: reset: augment versatile driver for integrator

Augment the Versatile reset driver to also handle the core
module reset sequence used on the Integrator/AP and
Integrator/CP.

Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>