sparc: leon3: Add debug_uart support to LEON3 serial driver.

Signed-off-by: Francois Retief <fgretief@spaceteq.co.za>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index d462244..eba96f4 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -98,6 +98,14 @@
 	  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_APBUART
+	depends on LEON3
+	bool "Gaisler APBUART"
+	help
+	  Select this to enable a debug UART using the serial_leon3 driver. You
+	  will need to provide parameters to make this work. The driver will
+	  be available until the real driver model serial is running.
+
 endchoice
 
 config DEBUG_UART_BASE