build: zephyr: Remove unused QEMU variable

This value is unused; it will be overridden by the main Makefile before it
is used. This is for the best since the value is also broken. Remove it.

Change-Id: Ibc5aae3f9967eb2b26a482425c3bbbaf44c0e2bb
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
1 file changed