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-zynq/cpu.c b/arch/arm/mach-zynq/cpu.c
index 5b6d765..74dddc2 100644
--- a/arch/arm/mach-zynq/cpu.c
+++ b/arch/arm/mach-zynq/cpu.c
@@ -52,7 +52,7 @@
 int arch_cpu_init(void)
 {
 	zynq_slcr_unlock();
-#ifndef CONFIG_SPL_BUILD
+#ifndef CONFIG_XPL_BUILD
 	/* Device config APB, unlock the PCAP */
 	writel(0x757BDF0D, &devcfg_base->unlock);
 	writel(0xFFFFFFFF, &devcfg_base->rom_shadow);