fsdev: Fix archs that dont use fsdev

Fix provided by: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

fsdev/qemu-fsdev-dummy.c

@@ -13,8 +13,16 @@
 #include <stdio.h>
 #include <string.h>
 #include "qemu-fsdev.h"
+#include "qemu-config.h"
 
 int qemu_fsdev_add(QemuOpts *opts)
 {
     return 0;
 }
+
+static void fsdev_register_config(void)
+{
+    qemu_add_opts(&qemu_fsdev_opts);
+    qemu_add_opts(&qemu_virtfs_opts);
+}
+machine_init(fsdev_register_config);