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-rockchip/rk3328/rk3328.c b/arch/arm/mach-rockchip/rk3328/rk3328.c
index c86d119..12ad17d 100644
--- a/arch/arm/mach-rockchip/rk3328/rk3328.c
+++ b/arch/arm/mach-rockchip/rk3328/rk3328.c
@@ -62,7 +62,7 @@
 
 int arch_cpu_init(void)
 {
-#ifdef CONFIG_SPL_BUILD
+#ifdef CONFIG_XPL_BUILD
 	u32 reg;
 
 	/* We do some SoC one time setting here. */