clk: meson: gxbb-ao: replace cec-32k with the dual divider

Replace the cec-32k clock of gxbb-ao with the simpler dual divider
driver. The dual divider implements only the dividing part. All the
other bits are now exposed using simple elements, such as gates and
muxes

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lkml.kernel.org/r/20181221160239.26265-5-jbrunet@baylibre.com