rpi: add 3 Model A+

Add Raspberry Pi 3 Model A+ to list of models, the revision code is 0xE
according to the list on raspberrypi.org.

Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
index 5062486..153a1fd 100644
--- a/board/raspberrypi/rpi/rpi.c
+++ b/board/raspberrypi/rpi/rpi.c
@@ -138,6 +138,11 @@
 		DTB_DIR "bcm2837-rpi-3-b-plus.dtb",
 		true,
 	},
+	[0xE] = {
+		"3 Model A+",
+		DTB_DIR "bcm2837-rpi-3-a-plus.dtb",
+		false,
+	},
 };
 
 static const struct rpi_model rpi_models_old_scheme[] = {