fix(intel): update certificate mask for FPGA Attestation

Update the certificate mask to 0xff to cover all certificate
in Agilex family.

Signed-off-by: Boon Khai Ng <boon.khai.ng@intel.com>
Signed-off-by: Sieu Mun Tang <sieu.mun.tang@intel.com>
Change-Id: Id40bc3aa4b3e4f7568a58581bbb03a75b0f20a0b