Added board_id = 0xc42

Reference http://www.raspberrypi.org/phpBB3/viewtopic.php?f=72&t=29944

Author: jncronin

hw/raspi.c

@@ -293,7 +293,7 @@ static void raspi_init(QEMUMachineInitArgs *args)
     raspi_binfo.kernel_filename = args->kernel_filename;
     raspi_binfo.kernel_cmdline = args->kernel_cmdline;
     raspi_binfo.initrd_filename = args->initrd_filename;
-    // raspi_binfo.board_id = board_id;
+    raspi_binfo.board_id = 0xc42;
 
     // Quick and dirty "selector"
     if (args->initrd_filename