edk2: Avoid VENDOR_BOOT verify if header version is <3

Do not check for vendor_boot validity if header version is
less than 3, as vendor_boot existence comes with header version
3 only.

Change-Id: I0e48afeaf817e62c0481f7d75d3028e9607a2834
Signed-off-by: Venkata Rao Kakani <vkakani@codeaurora.org>
1 file changed