zephyr: Add new vendors to local DTS bindings
Add lgc, intersil et al to the vendors list to fix
the device tree warnings.
TEST=zmake testall
BRANCH=none
# vendor-prefix<TAB>vendor name
cros-ec The Chromium OS Embedded Controller Project
cros The Chromium OS Embedded Controller Project
+intersil Intersil
+lgc LG Chem
+as3gwrc3ka Battery vendor
+smp Battery vendor
+aec Battery vendor
+powertech Battery vendor
+getac Battery vendor
