arch: fixup after fix to broken BuildID

Since commit [1], the Kunit tests have failed with a linker error:

ERROR:root:`.exit.text' referenced in section `.uml.exitcall.exit' of \
arch/um/drivers/virtio_uml.o: defined in discarded section `.exit.text' \
of arch/um/drivers/virtio_uml.o

There's a suggestion that this is due to the use of an older binutils
package.

This patch, likely to soon be replaced by an official upstream change,
makes the Kunit builds work again with binutils 2.34.

See [2] for discussion of the problem, and the origin of this solution/
workaround.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

[1] 99cb0d91 ("arch: fix broken BuildID for arm64 and riscv")
[2] https://lore.kernel.org/lkml/20230110191404.132594-1-sj@kernel.org/T/