To avoid NULL function pointer access. This happens on VG10, reboot
command hangs and have to power off/on to reboot the machine. This is
serial console log:
Signed-off-by: Philip Yang <Philip.Yang@amd.com> Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>