linux-wandboard

[ARM] Kirkwood: prepare for runtime-determined timer tick rate

Currently, kirkwood uses a hardcoded timer tick rate of 166 MHz, but
the actual timer tick rate varies between different members of the SoC
family.

This patch prepares for runtime determination of the timer tick rate.

Signed-off-by: Ronen Shitrit <rshitrit@marvell.com>