power: qpnp-fg-gen3: Add WA for oscillator drift on PM660

It is observed that on certain foundry devices, frequency of the
standby oscillator drifts with die temperature. Compensate
for this by correcting the FG time-base based on die temperature.

Change-Id: I0de19b9c342bf50568502b4de96897e159a8e143
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>