dt-bindings: clock: g12a-aoclk: expose CLKID_AO_CTS_OSCIN

When submitted v2 of the G12A AO-CLK IDs, the CLKID_AO_CTS_OSCIN was moved
to the internal non-exported bindings, but this clock is necessary for
the second AO-CEC-B module since it embeds the 32768Hz dual-divider
clock generator unlike the AO-CEC-A module.

Export it back to the public bindings.

Fixes: be3d960b ("dt-bindings: clk: add G12A AO Clock and Reset Bindings")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lkml.kernel.org/r/20190321092010.14382-1-narmstrong@baylibre.com