board: Use CONFIG_XPL_BUILD instead of CONFIG_SPL_BUILD

Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/ea/mx7ulp_com/mx7ulp_com.c b/board/ea/mx7ulp_com/mx7ulp_com.c
index 8f78937..d3a65fd 100644
--- a/board/ea/mx7ulp_com/mx7ulp_com.c
+++ b/board/ea/mx7ulp_com/mx7ulp_com.c
@@ -52,7 +52,7 @@
 	return 0;
 }
 
-#ifdef CONFIG_SPL_BUILD
+#ifdef CONFIG_XPL_BUILD
 #include <spl.h>
 
 #ifdef CONFIG_SPL_LOAD_FIT