device/Kconfig: Clarify ON_DEVICE_ROM_LOAD

It's only used for VGA ROMs.

Change-Id: I898765f79cbf5ccce871a3598b56eda83e5efaca
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/19805
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
1 file changed