power: qpnp-fg-gen3: Configure ESR timer at shutdown

On the PMW3100 wear platform which supports TWM mode, the FG
ESR timer (during TWM) can be increased as the system power
consumption is low. Add support for it by configuring the
ESR timer at shutdown.

Change-Id: I6cb2859437fcbcd1ffb1a73a190f0def86f9deaa
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>