s390/cio: Add missing MODULE_DESCRIPTION() macros

With ARCH=s390, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/s390/cio/ccwgroup.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/s390/cio/vfio_ccw.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240715-md-s390-drivers-s390-cio-v2-1-97eaa6971124@quicinc.comSigned-off-by: Vasily Gorbik <gor@linux.ibm.com>

drivers/s390/cio/ccwgroup.c

@@ -550,4 +550,5 @@ void ccwgroup_remove_ccwdev(struct ccw_device *cdev)
 	put_device(&gdev->dev);
 }
 EXPORT_SYMBOL(ccwgroup_remove_ccwdev);
+MODULE_DESCRIPTION("ccwgroup bus driver");
 MODULE_LICENSE("GPL");

drivers/s390/cio/vfio_ccw_drv.c

@@ -488,4 +488,5 @@ static void __exit vfio_ccw_sch_exit(void)
 module_init(vfio_ccw_sch_init);
 module_exit(vfio_ccw_sch_exit);
 
+MODULE_DESCRIPTION("VFIO based Subchannel device driver");
 MODULE_LICENSE("GPL v2");