bad case won't follow normal sense, it will not enable vga1 as usual, but vga2,3,4 is on.

Signed-off-by: Clark Zheng <clark.zheng@amd.com>
Reviewed-by: Tony Cheng <tony.cheng@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>