Also don't define the default as this results in spurious lines in the
.config.
The only difference in the generated config.h is that for most board
ARCH_RISCV_M goes from 1 to 0. This should not matter.
Change-Id: I3e8c1cc5696d621e243696a3b5e34f62ab69a688
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31311
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>