Make a variable that holds `$(board_build)/heads-$(BOARD)-$(HEADS_GIT_VERSION)` because that's so long and repeated so many times, e.g. `BUILD_ROM_PREFIX=$(board_build)/heads-$(BOARD)-$(HEADS_GIT_VERSION)`

[tlaurion]

If you want, you could make a variable that holds $(board_build)/heads-$(BOARD)-$(HEADS_GIT_VERSION) because that's so long and repeated so many times, e.g. BUILD_ROM_PREFIX=$(board_build)/heads-$(BOARD)-$(HEADS_GIT_VERSION).

Originally posted by @JonathonHall-Purism in https://github.com/linuxboot/heads/pull/1834#discussion_r1829737515_