Add MODULE_DESCRIPTION to dummy-irq.c and lkdtm.c in drivers/misc

This starts to address
https://bugzilla.kernel.org/show_bug.cgi?id=10770

Signed-off-by: Terry Chia <terrycwk1994@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/lkdtm.c b/drivers/misc/lkdtm.c
index d66a2f2..b5abe34 100644
--- a/drivers/misc/lkdtm.c
+++ b/drivers/misc/lkdtm.c
@@ -870,3 +870,4 @@
 module_exit(lkdtm_module_exit);
 
 MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Kprobe module for testing crash dumps");