charger/rt946x: fix mt6370 IEOC inaccuracy
charger/rt946x: fix mt6370 IEOC inaccuracy

mt6370's IEOC is inaccurate when charging current < 900mA; the power
path only partially turned on under such situation. Hence, we
have to raise the IEOC setting if the current is under 900mA to
compensate the IEOC original setting.

BUG=b:144532905
BRANCH=kukui
TEST=ensure IEOC is raised when Ichg < 900mA.

Change-Id: I9f1575bb707bc91e428c06a93c4682dde22d90fc
Signed-off-by: Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1924167
Reviewed-by: Ting Shen <c671d3efec3d7e7e285f3788bf0d1ba4c8605b78@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec