don't hardcode the check based on whether the current
project is grub. instead, define "btype" in target.cfg
if unset, we assume kconfig and permit kconfig commands
e.g. make menuconfig, make silentoldconfig, etc
this is to avoid the deadliest of sins:
project-specific hacks
Signed-off-by: Leah Rowe <leah@libreboot.org>
cf4f828dbe