x86, efi: Fix NumberOfRvaAndSizes field in PE32 header for EFI_STUB

We've actually got six data directories in the header, not one. Even
though the firmware loader doesn't seem to mind, when we come to sign
the kernel image the signing tool thinks that there is no Certificate
Table data directory, even though we've allocated space for one.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1332520506-6472-4-git-send-email-jordan.l.justen@intel.com


Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>