serial: 8250_early: add xscale earlycon support

After commit 3a50365d ("serial: 8250: Add OF support for Xscale
variant"), 8250_of can support the xscale variant. Now, let's add
the earlycon support for xscale too.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20240711160720.3488-3-jszhang@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -178,6 +178,7 @@ static int __init early_serial8250_rs2_setup(struct earlycon_device *device,
 
 	return early_serial8250_setup(device, options);
 }
+OF_EARLYCON_DECLARE(uart, "intel,xscale-uart", early_serial8250_rs2_setup);
 OF_EARLYCON_DECLARE(uart, "mrvl,mmp-uart", early_serial8250_rs2_setup);
 OF_EARLYCON_DECLARE(uart, "mrvl,pxa-uart", early_serial8250_rs2_setup);