Ensure partition_tag is always set correctly

partition_tag is now set to either VENDOR_, OEM_, or ODM_
even when LOCAL_[VENDOR|OEM|ODM]_MODULE isn't set but LOCAL_MODULE_PATH
is explicitly set to under $(TARGET_OUT_[VENDOR|OEM|ODM]).

Test: build walleye

Change-Id: I0f902061889fe0af1c39f6222e54faa80dd15794