power: qcom: qbg: update OCV boost compensation into SDAM

Add boost headroom compensation on valid OCV value
and set it into SDAM to enable charger-boost to
operate optimally.

Change-Id: Iae66525b6899368061baeb50530c9c61488b5e2c
Signed-off-by: Hui Liu <huliu@codeaurora.org>