USB: serial: add missing MODULE_DESCRIPTION() macros

Since commit 1fffe7a3 ("script: modpost: emit a warning when the
description is missing"), ARCH=x86 make allmodconfig && make W=1 reports:

WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/ch341.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/usb_debug.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/mxuport.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/navman.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/qcaux.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/usb-serial-simple.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/serial/symbolserial.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
[ johan: amend commit message with commit introducing W=1 warning;
         tweak some descriptions ]
Signed-off-by: Johan Hovold <johan@kernel.org>

drivers/usb/serial/ch341.c

@@ -863,4 +863,5 @@ static struct usb_serial_driver * const serial_drivers[] = {
 
 module_usb_serial_driver(serial_drivers, id_table);
 
+MODULE_DESCRIPTION("Winchiphead CH341 USB Serial driver");
 MODULE_LICENSE("GPL v2");

drivers/usb/serial/mxuport.c

@@ -1315,4 +1315,5 @@ module_usb_serial_driver(serial_drivers, mxuport_idtable);
 
 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 MODULE_AUTHOR("<support@moxa.com>");
+MODULE_DESCRIPTION("Moxa UPORT USB Serial driver");
 MODULE_LICENSE("GPL");

drivers/usb/serial/navman.c

@@ -112,4 +112,5 @@ static struct usb_serial_driver * const serial_drivers[] = {
 
 module_usb_serial_driver(serial_drivers, id_table);
 
+MODULE_DESCRIPTION("Navman USB Serial driver");
 MODULE_LICENSE("GPL v2");

drivers/usb/serial/qcaux.c

@@ -84,4 +84,5 @@ static struct usb_serial_driver * const serial_drivers[] = {
 };
 
 module_usb_serial_driver(serial_drivers, id_table);
+MODULE_DESCRIPTION("Qualcomm USB Auxiliary Serial Port driver");
 MODULE_LICENSE("GPL v2");

drivers/usb/serial/symbolserial.c

@@ -190,4 +190,5 @@ static struct usb_serial_driver * const serial_drivers[] = {
 
 module_usb_serial_driver(serial_drivers, id_table);
 
+MODULE_DESCRIPTION("Symbol USB barcode to serial driver");
 MODULE_LICENSE("GPL v2");

drivers/usb/serial/usb-serial-simple.c

@@ -163,4 +163,5 @@ static const struct usb_device_id id_table[] = {
 MODULE_DEVICE_TABLE(usb, id_table);
 
 module_usb_serial_driver(serial_drivers, id_table);
+MODULE_DESCRIPTION("USB Serial 'Simple' driver");
 MODULE_LICENSE("GPL v2");

drivers/usb/serial/usb_debug.c

@@ -104,4 +104,5 @@ static struct usb_serial_driver * const serial_drivers[] = {
 };
 
 module_usb_serial_driver(serial_drivers, id_table_combined);
+MODULE_DESCRIPTION("USB Debug cable driver");
 MODULE_LICENSE("GPL v2");