selftests: vm: add CONFIG_SYSVIPC=y to the config fragment

vm tests rely on shared memory settings. Enable system V IPC to run these
tests.

Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>