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/x86/cpu/broadwell/Makefile b/arch/x86/cpu/broadwell/Makefile
index 3e1f76d..6c6d0ed 100644
--- a/arch/x86/cpu/broadwell/Makefile
+++ b/arch/x86/cpu/broadwell/Makefile
@@ -6,12 +6,12 @@
 obj-$(CONFIG_$(SPL_TPL_)X86_32BIT_INIT) += cpu_full.o
 
 ifdef CONFIG_SPL
-ifndef CONFIG_SPL_BUILD
+ifndef CONFIG_XPL_BUILD
 obj-y += cpu_from_spl.o
 obj-y += cpu_full.o
 obj-y += refcode.o
 endif
-ifndef CONFIG_SPL_BUILD
+ifndef CONFIG_XPL_BUILD
 # obj-y += cpu_from_spl.o
 obj-y += adsp.o
 obj-y += sata.o