serial: 8250: remove the redundant include

The serial_core.h file have been included in header file
serial_8250.h. so remove the "#include <serial_core.h>" in
some 8250 serial drivers, because they have included the header file
serial_8250.h.
Signed-off-by: NWang Long <long.wanglong@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250_core.c

@@ -31,7 +31,6 @@
 #include <linux/tty.h>
 #include <linux/ratelimit.h>
 #include <linux/tty_flip.h>
-#include <linux/serial_core.h>
 #include <linux/serial.h>
 #include <linux/serial_8250.h>
 #include <linux/nmi.h>

drivers/tty/serial/8250/8250_dw.c

@@ -17,7 +17,6 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/serial_8250.h>
-#include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>

drivers/tty/serial/8250/8250_early.c

@@ -29,7 +29,6 @@
 #include <linux/tty.h>
 #include <linux/init.h>
 #include <linux/console.h>
-#include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/serial.h>
 #include <linux/serial_8250.h>

drivers/tty/serial/8250/8250_em.c

@@ -21,7 +21,6 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/serial_8250.h>
-#include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>

drivers/tty/serial/8250/8250_hp300.c

@@ -10,7 +10,6 @@
 #include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/serial.h>
-#include <linux/serial_core.h>
 #include <linux/serial_8250.h>
 #include <linux/delay.h>
 #include <linux/dio.h>

drivers/tty/serial/8250/8250_omap.c

@@ -11,7 +11,6 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/serial_8250.h>
-#include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/tty_flip.h>
 #include <linux/platform_device.h>