Allow building with BLUETOOTH flag from Makefile.
Allow building with BLUETOOTH flag from Makefile.

openxc/vi-firmware,openxc/vi-firmware,mgiannikouris/vi-firmware,openxc/vi-firmware,mgiannikouris/vi-firmware,ene-ilies/vi-firmware,ene-ilies/vi-firmware,openxc/vi-firmware,mgiannikouris/vi-firmware,ene-ilies/vi-firmware,ene-ilies/vi-firmware,mgiannikouris/vi-firmware