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/include/asm/arch-mx6/mx6-ddr.h b/arch/arm/include/asm/arch-mx6/mx6-ddr.h
index dbc97b2..ad9c1ac 100644
--- a/arch/arm/include/asm/arch-mx6/mx6-ddr.h
+++ b/arch/arm/include/asm/arch-mx6/mx6-ddr.h
@@ -5,7 +5,7 @@
 #ifndef __ASM_ARCH_MX6_DDR_H__
 #define __ASM_ARCH_MX6_DDR_H__
 
-#ifndef CONFIG_SPL_BUILD
+#ifndef CONFIG_XPL_BUILD
 #ifdef CONFIG_MX6Q
 #include "mx6q-ddr.h"
 #else
@@ -488,7 +488,7 @@
 		  const struct mx6_mmdc_calibration *,
 		  const void *);
 
-#endif /* CONFIG_SPL_BUILD */
+#endif /* CONFIG_XPL_BUILD */
 
 #define MX6_MMDC_P0_MDCTL	0x021b0000
 #define MX6_MMDC_P0_MDPDC	0x021b0004