power: qpnp-charger: correct IBATSAFE_MIN_MA setting error

According SWI(software interface), IBAT_SAFE
should be calculated by I = X*50(X is the value of
SMBB_CHGR_IBAT_SAFE), but previously software made it
to I = 100 + X*50, correct it.

Change-Id: Iff5c3d60e3ca66c0bfbbca21acaed6d610a65859
CRs-Fixed: 515160
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>