serial: pch_uart: Fix build warning when CONFIG_DEBUG_FS=n

Add CONFIG_DEBUG_FS to 'char name' in order to fix the following
build warning, because 'char name' is used only when CONFIG_DEBUG_FS
is enabled.

drivers/tty/serial/pch_uart.c:1765:7: warning: unused variable 'name' [-Wunused-variable]
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/pch_uart.c

@@ -1762,7 +1762,9 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	int fifosize;
 	int port_type;
 	struct pch_uart_driver_data *board;
+#ifdef CONFIG_DEBUG_FS
 	char name[32];	/* for debugfs file name */
+#endif
 
 	board = &drv_dat[id->driver_data];
 	port_type = board->port_type;