rename CFG_ macros to CONFIG_SYS

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/cpu/at32ap/start.S b/cpu/at32ap/start.S
index 907e9b1..d37a46e 100644
--- a/cpu/at32ap/start.S
+++ b/cpu/at32ap/start.S
@@ -188,7 +188,7 @@
 	.align	2
 	.type	sp_init,@object
 sp_init:
-	.long	CFG_INIT_SP_ADDR
+	.long	CONFIG_SYS_INIT_SP_ADDR
 got_init:
 	.long	3b - _GLOBAL_OFFSET_TABLE_