ivshmem: add device description

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 9023f95..7be3d5e 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -925,6 +925,7 @@
     dc->props = ivshmem_properties;
     dc->vmsd = &ivshmem_vmsd;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    dc->desc = "Inter-VM shared memory";
 }
 
 static const TypeInfo ivshmem_info = {