lillipup: fix Dut can't wake battery up from shutdown mode
lillipup: fix Dut can't wake battery up from shutdown mode

1. Override "board_battery_is_initialized" to report correct battery
   initial state. That's same as eldrid board.
2. Once return BP_NOT_SURE for uninitialized battery, EC may require
   pre-charge current to wake battery up.
3. It shouldn't keep return BP_NO that it may cause EC not to set
   pre-charge current and cause battery keep in shutdown mode.

BUG=b:175767091
BRANCH=firmware-volteer-13521.B
TEST=make buildall, Verify battery which is under shutdown mode and wake
it up.

Signed-off-by: amber.chen <21140f70e84af3207302c4be977fd739c3f5bcc2@lcfc.corp-partner.google.com>
Change-Id: I8b4736553224cf59ac098d41f615742590ef4a20
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2597134
Reviewed-by: Zhuohao Lee <916bf7ddbf0565669e59e3cb2b613381a48066c0@chromium.org>

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