zephyr: herobrine: Define battery-level property as int range
zephyr: herobrine: Define battery-level property as int range

Currently battery-level property is defined using enums. This patch
changes this to use int range instead.

BRANCH=None
BUG=b:233953617
TEST=Manual test on Lazor by modifying nodes to include battery-level
range, use battfake to set different levels and observe LED behavior.

Cq-Depend: chromium:3669088
Signed-off-by: Parth Malkan <c3d09dcbffc3a0a63125afed46f55e5cbf5bb3a9@google.com>
Change-Id: I18ef922a41ce17d509f03a1774e9d9437fc7065d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3669089
Reviewed-by: Wai-Hong Tam <04b587fdf5845741a0c5a8b9cd59ca72d73ef8fc@google.com>

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