iodevs.pl: export base addresses to Verilog

Export contants with the device base addresses into the Verilog
output.

tools/iodevs.pl

@@ -180,9 +180,13 @@ sub generate_verilog($)
 	if ($xdev) {
 	    printf $out "\twire [%2d:0] iodev_valid_%s = xdev_valid[%d:%d];\n",
 		$dcount-1, $name, $nxdev+$dcount-1, $nxdev;
+	    printf $out "\tlocalparam [31:0] iodev_%s_base = 32'h%08x;\n",
+		$name, base($nxdev, $xdev_addr_bits, $xdev_addr_shift);
 	} else {
 	    printf $out "\twire [%2d:0] iodev_valid_%s = iodev_valid[%d:%d];\n",
 		$dcount-1, $name, $ndev+$dcount-1, $ndev;
+	    printf $out "\tlocalparam [31:0] iodev_%s_base = 32'h%08x;\n",
+		$name, base($ndev, $iodev_addr_bits, $iodev_addr_shift);
 	}
 
 	printf $out "\ttri1 [%2d:0] iodev_wait_n_%s;\n", $dcount-1, $name;