tty: rpmsg: Define tty name via constant string literal

Driver uses already twice the same string literal.

Define it in one place, so every user will have this
name consistent.

Signed-off-by: Andy Shevchenko <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/rpmsg_tty.c

···
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 
+#define RPMSG_TTY_NAME	"ttyRPMSG"
 #define MAX_TTY_RPMSG	32
 
 static DEFINE_IDR(tty_idr);	/* tty instance id */
···
 
 	dev_set_drvdata(dev, cport);
 
-	dev_dbg(dev, "New channel: 0x%x -> 0x%x : ttyRPMSG%d\n",
+	dev_dbg(dev, "New channel: 0x%x -> 0x%x: " RPMSG_TTY_NAME "%d\n",
 		rpdev->src, rpdev->dst, cport->id);
 
 	return 0;
···
 		return PTR_ERR(rpmsg_tty_driver);
 
 	rpmsg_tty_driver->driver_name = "rpmsg_tty";
-	rpmsg_tty_driver->name = "ttyRPMSG";
+	rpmsg_tty_driver->name = RPMSG_TTY_NAME;
 	rpmsg_tty_driver->major = 0;
 	rpmsg_tty_driver->type = TTY_DRIVER_TYPE_CONSOLE;