tty: move tty_ldisc_receive_buf to tty_flip.h

It's the only remaining tty_buffer.c prototype residing in tty.h. Move
it along others to tty_flip.h.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723103147.18250-6-jslaby@suse.czSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/tty.h

@@ -622,9 +622,6 @@ static inline int tty_port_users(struct tty_port *port)
 	return port->count + port->blocked_open;
 }
 
-extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
-				 const char *f, int count);
-
 /* n_tty.c */
 extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 #ifdef CONFIG_TTY

include/linux/tty_flip.h

@@ -4,6 +4,8 @@
 
 #include <linux/tty.h>
 
+struct tty_ldisc;
+
 extern int tty_buffer_set_limit(struct tty_port *port, int limit);
 extern unsigned int tty_buffer_space_avail(struct tty_port *port);
 extern int tty_buffer_request_room(struct tty_port *port, size_t size);
@@ -39,6 +41,9 @@ static inline int tty_insert_flip_string(struct tty_port *port,
 	return tty_insert_flip_string_fixed_flag(port, chars, TTY_NORMAL, size);
 }
 
+int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
+		const char *f, int count);
+
 extern void tty_buffer_lock_exclusive(struct tty_port *port);
 extern void tty_buffer_unlock_exclusive(struct tty_port *port);