MIPS: lantiq: falcon clocks were not enabled properly

As a result of a non populated ->bits field inside the clock struct, the clock
domains were never powered on the Falcon. Until now we only used domains that
were also used and powered by the bootloader.

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4234/