tty/serial: atmel: move atmel_serial header into driver directory

atmel_serial.h is only used by atmel_serial.c, so there's no need for
it to lie in include/linux.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -8283,7 +8283,7 @@ MICROCHIP / ATMEL AT91 / AT32 SERIAL DRIVER
 M:	Richard Genoud <richard.genoud@gmail.com>
 S:	Maintained
 F:	drivers/tty/serial/atmel_serial.c
-F:	include/linux/atmel_serial.h
+F:	drivers/tty/serial/atmel_serial.h
 
 MICROCHIP / ATMEL DMA DRIVER
 M:	Ludovic Desroches <ludovic.desroches@microchip.com>

drivers/tty/serial/atmel_serial.c

@@ -38,7 +38,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
 #include <linux/atmel_pdc.h>
-#include <linux/atmel_serial.h>
 #include <linux/uaccess.h>
 #include <linux/platform_data/atmel.h>
 #include <linux/timer.h>
@@ -71,6 +70,7 @@
 #include <linux/serial_core.h>
 
 #include "serial_mctrl_gpio.h"
+#include "atmel_serial.h"
 
 static void atmel_start_rx(struct uart_port *port);
 static void atmel_stop_rx(struct uart_port *port);