ARM: multi_v7_defconfig: enable rk808 clkout module

The rk808 supplies two clock outputs with one going back into the soc as
32kHz supply, supplying some core soc clocks with it. The system can boot
without it being present, but it is needed for example as source clock
for the thermal driver.

Signed-off-by: Heiko Stuebner <heiko.stuebner@collabora.com>
Signed-off-by: Olof Johansson <olof@lixom.net>