clk: sunxi: mod1 clock support

The module 1 type of clocks consist of a gate and a mux and are used on
the audio blocks to mux and gate the PLL2 outputs for AC97, IIS or
SPDIF. This commit adds support for them on the sunxi clock driver.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>