flo: remove duplicate vendor include

-include vendor/asus/flo/BoardConfigVendor.mk is in BoardConfigCommon.mk
so that deb can inherit it. Comment it out of BoardConfig.mk.

Change-Id: I87f1b6825bba666a823b06372fc5ead1e9650c9d
Prepare for TWRP

Change-Id: I687cc6ababb2907d231ae60e894fc17b5ea6a8db