uefi-capsule: Do not generate a capsule header for the FMP GUID
uefi-capsule: Do not generate a capsule header for the FMP GUID

In theory, hardware with FMP should have fw_type=0x4 in the ESRT which
sets `_NO_CAPSULE_HEADER_FIXUP` -- but in reality that is not always
the case.

fwupd/fwupd,fwupd/fwupd,fwupd/fwupd,fwupd/fwupd