We assumed that ${BOARD} and ${BOARD_FAMILY} are always the same and
thus interchangeable. That isn't always the case so use ${BOARD} proper
for when we mean the exact BOARD name we are building for vs the
BOARD_FAMILY.
We also add .dts files for board variants within a board family, such
that we have a .dts matching each board name.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Kumar Gala