serial/serial_arc: Implement debug serial

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 1aab032..8777909 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -197,6 +197,15 @@
 	  driver will be available until the real driver model serial is
 	  running.
 
+config DEBUG_ARC_SERIAL
+	bool "ARC UART"
+	depends on ARC_SERIAL
+	help
+	  Select this to enable a debug UART using the ARC UART driver.
+	  You will need to provide parameters to make this work. The
+	  driver will be available until the real driver model serial is
+	  running.
+
 config DEBUG_UART_ATMEL
 	bool "Atmel USART"
 	help