serial: xuartps: Enable OF earlycon support

Support early console setup via DT for all listed compatible strings.
Remove EARLYCON_DECLARE which was done by:
"Use common framework for earlycon declarations"
(sha1: 2eaa790989e03900298ad24f77f1086dbbc1aebd)
when OF_EARLYCON_DECLARE is defined.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/xilinx_uartps.c

@@ -1077,7 +1077,9 @@ static int __init cdns_early_console_setup(struct earlycon_device *device,
 
 	return 0;
 }
-EARLYCON_DECLARE(cdns, cdns_early_console_setup);
+OF_EARLYCON_DECLARE(cdns, "xlnx,xuartps", cdns_early_console_setup);
+OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p8", cdns_early_console_setup);
+OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p12", cdns_early_console_setup);
 
 /**
  * cdns_uart_console_write - perform write operation