msm: clock-krait-8974: Change ref count behavior at boot

Set up the refcount of the L2 clock to be equal to the number of online
cores. This allows the clients of the CPU/L2 clocks that enable/disable
them to be agnostic of the no. of cores that are online.

For example, the CPU idle code can call clk_disable() on the L2 clock
from all the cores' idle path without having to figure out if it's the
last active core. If the core is the last core that's active, the ref
count will go from 1 to 0 and the clock would get disabled.

Also update cpufreq driver behavior to accomodate this change.

Change-Id: If253a85ad62f0a6a78452dafc7afe86bd112cf73
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>