power: qpnp-fg-gen4: Fix esr calibration during discharge

Parsing ESR calibration window is skipped when qcom,fg-esr-calib-dischg
is enabled. Also ESR discharge timer is disabled when ESR fast
calibration is disabled. Fix this by enabling ESR discharge timer when
qcom,fg-esr-calib-dischg is enabled.

Change-Id: I7b831f851005ab19275ea36b40c249e2e9f968c7
Signed-off-by: Shyam Kumar Thella <sthella@codeaurora.org>