vfio-mdev: add missing MODULE_DESCRIPTION() macros

Since commit 1fffe7a34c89 ("script: modpost: emit a warning when the
description is missing"), a module without a MODULE_DESCRIPTION() will
result in a warning with make W=1. The following warnings are being
observed in samples/vfio-mdev:

WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mtty.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mdpy.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mdpy-fb.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mbochs.o

Add the missing invocations of the MODULE_DESCRIPTION() macro to these
modules. And in the case of mtty.c, remove the now redundant instance
of the MODULE_INFO() macro.

Signed-off-by: Jeff Johnson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alex Williamson <[e-mail]>

samples/vfio-mdev/mbochs.c

···
 #define STORE_LE32(addr, val)	(*(u32 *)addr = val)
 
 
+MODULE_DESCRIPTION("Mediated virtual PCI display host device driver");
 MODULE_LICENSE("GPL v2");
 
 static int max_mbytes = 256;

samples/vfio-mdev/mdpy-fb.c

···
 module_init(mdpy_fb_init);
 
 MODULE_DEVICE_TABLE(pci, mdpy_fb_pci_table);
+MODULE_DESCRIPTION("Framebuffer driver for mdpy (mediated virtual pci display device)");
 MODULE_LICENSE("GPL v2");

samples/vfio-mdev/mdpy.c

···
 #define STORE_LE32(addr, val)	(*(u32 *)addr = val)
 
 
+MODULE_DESCRIPTION("Mediated virtual PCI display host device driver");
 MODULE_LICENSE("GPL v2");
 
 #define MDPY_TYPE_1 "vga"

samples/vfio-mdev/mtty.c

···
 module_exit(mtty_dev_exit)
 
 MODULE_LICENSE("GPL v2");
-MODULE_INFO(supported, "Test driver that simulate serial port over PCI");
+MODULE_DESCRIPTION("Test driver that simulate serial port over PCI");
 MODULE_VERSION(VERSION_STRING);
 MODULE_AUTHOR(DRIVER_AUTHOR);