power: qpnp-fg-gen4: Reduce ESR fast calibration time to 50s

For a fresh boot, FG calibrates the impedance of the battery rapidly.
This causes the system to wake about 10 ~ 30 times in a span of 300
seconds, which is deemed too long to keep waking up the device from
sleep, while 50s is an acceptable value.

Change it.

Change-Id: I97f6bb94b4f4e75727cdc41e4561028cc3243a47
Signed-off-by: Harry Yang <harryy@codeaurora.org>