arch: 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/arch/arm/mach-omap2/omap5/hwinit.c b/arch/arm/mach-omap2/omap5/hwinit.c
index 7f41e85..42f9c63 100644
--- a/arch/arm/mach-omap2/omap5/hwinit.c
+++ b/arch/arm/mach-omap2/omap5/hwinit.c
@@ -50,7 +50,7 @@
 		writel(pad->val, base + pad->offset);
 }
 
-#ifdef CONFIG_SPL_BUILD
+#ifdef CONFIG_XPL_BUILD
 /* LPDDR2 specific IO settings */
 static void io_settings_lpddr2(void)
 {