on 3050micro, we disable seabios as a primary payload,
making grub a pribary payload instead.
the way it worked, the roms were still named seagrub
and the seabios rom would be compiled, but with the wrong
path, so seabios wouldn't be executed; seabios would hang
anyway, on this board.
instead, engineer it in such a way as to disable seabios_
images on this board. also, rename seagrub_ to grub_.
i normally only permit seagrub, and not grub, but i make an
exception for 3050micro because we know grub works, but seabios
currently hangs on this board (which means no bsd).
Signed-off-by: Leah Rowe <leah@libreboot.org>