openrisc/cputimer: Perparation for Multicore

openrisc/cputimer: Perparation for Multicore

In order to support multicore system we move some of the previously
static state variables into the state of each core.

On the other hand in order to allow timers to be synced between each
code the ttcr (tick timer count register) is moved out of the core.
This is not as per real hardware spec which has a separate timer counter
per core, but it seems the most simple way to keep each clock in sync.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>