qemu_firmware: Don't skip autoselection for ROM

qemu_firmware: Don't skip autoselection for ROM

It's possible to have firmware descriptors for builds intended to
be loaded as ROM, as is the case for those loaded as pflash.
There is no reason to skip firmware autoselection in those cases,
and doing so prevents useful information from being filled in.

After this change, the firmware-manual-efi-tdx test case is
augmented with some additional information. Even more information
will be filled in later, when we improve the matching logic.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>