serial: mps2-uart: add support for early console

This adds support early console for MPS2 UART which can be enabled via
earlycon=mps2,0x40004000

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 3b0a9b3..331638d 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1452,6 +1452,7 @@
 	bool "MPS2 UART console support"
 	depends on SERIAL_MPS2_UART
 	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
 
 config SERIAL_MPS2_UART
 	bool "MPS2 UART port"