pch_uart: Add module parameter descriptions

Document default_baud and user_uartclk module parameters.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
CC: Tomoya MORINAGA <tomoya.rohm@gmail.com>
CC: Feng Tang <feng.tang@intel.com>
CC: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/pch_uart.c

@@ -1864,4 +1864,8 @@ module_exit(pch_uart_module_exit);
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Intel EG20T PCH UART PCI Driver");
 module_param(default_baud, uint, S_IRUGO);
+MODULE_PARM_DESC(default_baud,
+                 "Default BAUD for initial driver state and console (default 9600)");
 module_param(user_uartclk, uint, S_IRUGO);
+MODULE_PARM_DESC(user_uartclk,
+                 "Override UART default or board specific UART clock");