reset: add support for the Meson-A1 SoC Reset Controller

The number of RESET registers and offset of RESET_LEVEL register for
Meson-A1 are different from previous SoCs, In order to describe these
differences, we introduce the struct meson_reset_param.

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Xingyu Chen <xingyu.chen@amlogic.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>