serial: max310x: Fix build error

config: make ARCH=alpha allyesconfig

All error/warnings:

 drivers/tty/serial/max310x.c: In function 'max310x_ioctl':
>> drivers/tty/serial/max310x.c:905:7: error: 'TIOCSRS485' undeclared (first use in this function)
 drivers/tty/serial/max310x.c:905:7: note: each undeclared identifier is reported only once for each function it appears in
>> drivers/tty/serial/max310x.c:906:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
>> drivers/tty/serial/max310x.c:929:7: error: 'TIOCGRS485' undeclared (first use in this function)
>> drivers/tty/serial/max310x.c:938:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
 cc1: some warnings being treated as errors
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/max310x.c

@@ -24,9 +24,10 @@
 #include <linux/regmap.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
+#include <linux/spi/spi.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
-#include <linux/spi/spi.h>
+#include <uapi/asm-generic/ioctls.h>
 
 #define MAX310X_NAME			"max310x"
 #define MAX310X_MAJOR			204