MIPS: BCM63XX: fix BCM6345 clocks bits

MIPS: BCM63XX: fix BCM6345 clocks bits

BCM6345 has an intermediate 16-bits wide test control register between the
peripheral identifier register, and its clock control register is only 16-bits
wide contrary to other platforms where it is 32-bits wide. By shifting all
clocks bits by 16-bits to the left we ensure they get written to the proper
clock control register, without adding specific BCM6345 handling in the clock
code.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4555/
Signed-off-by: John Crispin <blogic@openwrt.org>