sp_min: Implement `sp_min_plat_runtime_setup()`

On ARM platforms before exiting from SP_MIN ensure that
the default console is switched to the runtime serial port.

Change-Id: I0ca0d42cc47e345d56179eac16aa3d6712767c9b
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
diff --git a/bl32/sp_min/sp_min_main.c b/bl32/sp_min/sp_min_main.c
index 45ad03f..73a5d69 100644
--- a/bl32/sp_min/sp_min_main.c
+++ b/bl32/sp_min/sp_min_main.c
@@ -176,6 +176,12 @@
 	 * corresponding to the desired security state after the next ERET.
 	 */
 	sp_min_prepare_next_image_entry();
+
+	/*
+	 * Perform any platform specific runtime setup prior to cold boot exit
+	 * from SP_MIN.
+	 */
+	sp_min_plat_runtime_setup();
 }
 
 /******************************************************************************