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-imx/imx8ulp/clock.c b/arch/arm/mach-imx/imx8ulp/clock.c
index fadf165..c390f20 100644
--- a/arch/arm/mach-imx/imx8ulp/clock.c
+++ b/arch/arm/mach-imx/imx8ulp/clock.c
@@ -519,7 +519,7 @@
 	return pcc_clock_get_rate(lpuart_pcc[index], lpuart_pcc_slots[index]);
 }
 
-#ifndef CONFIG_SPL_BUILD
+#ifndef CONFIG_XPL_BUILD
 /*
  * Dump some core clockes.
  */