gimble: revise battery LED behavior
gimble: revise battery LED behavior

Modify LED behavior to meet the revised specification

BUG=b:193600290
BRANCH=none
TEST=make -j BOARD=gimble

Signed-off-by: Will Tsai <7b3a2764695a2e44000ae6070fceccd181e4303d@wistron.corp-partner.google.com>
Change-Id: I3961b8083d30e582320cad1e4852746367e9a0a1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3312514
Reviewed-by: Boris Mittelberg <46897f4fb5cad4b1d5146ad1fd460d7f4825bbf7@google.com>

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