[build] Avoid generating ROMs with "match-any" vendor or device IDs

A PCI_ROM() entry containing a vendor or device ID of PCI_ANY_ID
(0xffff) indicates to pci_find_driver() that the entry's vendor or
device ID should be ignored when matching against the device's vendor
or device ID.  It does not represent a PCI ROM that should be built.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/util/parserom.pl

          \s*.*\s*		   # Driver data
        \)/x ) {
     ( my $vendor, my $device, my $image, my $desc ) = ( lc $1, lc $2, $3, $4 );
+    next if ( $vendor eq "ffff" ) || ( $device eq "ffff" );
     rom ( "pci", lc "${vendor}${device}", $desc, $vendor, $device );
     rom ( "pci", $image, $desc, $vendor, $device, 1 );
   } elsif ( /^\s*ISA_ROM\s*\(