This patch toggles the ring oscillator state across cluster idle
as DFLL loses its state. We dont want garbage values being written
to the pmic when we enter cluster idle state, so enable "open loop"
when we enter CC6 and restore the state to "closed loop" on exit.

Change-Id: I56f4649f57bcc651d6c415a6dcdc978e9444c97b
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>