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/freescale/ls1046aqds/ddr.c b/board/freescale/ls1046aqds/ddr.c
index ac1b604..5779033 100644
--- a/board/freescale/ls1046aqds/ddr.c
+++ b/board/freescale/ls1046aqds/ddr.c
@@ -107,7 +107,7 @@
 {
 	phys_size_t dram_size;
 
-#if defined(CONFIG_SPL) && !defined(CONFIG_SPL_BUILD)
+#if defined(CONFIG_SPL) && !defined(CONFIG_XPL_BUILD)
 	gd->ram_size = fsl_ddr_sdram_size();
 
 	return 0;