Add support for STX GP3SSA (stxssa) Board

Signed-off-by Dan Malek, <dan@embeddedalley.com>
diff --git a/Makefile b/Makefile
index 94cda54..2fe9a46 100644
--- a/Makefile
+++ b/Makefile
@@ -1771,6 +1771,9 @@
 stxgp3_config:		unconfig
 	@$(MKCONFIG) $(@:_config=) ppc mpc85xx stxgp3
 
+stxssa_config:		unconfig
+	@$(MKCONFIG) $(@:_config=) ppc mpc85xx stxssa
+
 TQM8540_config		\
 TQM8541_config		\
 TQM8555_config		\