ARC: [arcfpga] stdout-path now suffices for earlycon/console

With recent improvements to serial/of core from Grant and Rob,
stdout-path alone suffices for setting up earlycon/console.

arc_uart driver is already equipped to handle that, switch the DT now.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arc/boot/dts/angel4.dts

@@ -17,7 +17,8 @@
 	interrupt-parent = <&intc>;
 
 	chosen {
-		bootargs = "earlycon=arc_uart,mmio32,0xc0fc1000,115200n8 console=ttyARC0,115200n8";
+		bootargs = "earlycon";
+		stdout-path = &arcuart0;
 	};
 
 	aliases {