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/powerpc/cpu/mpc8xxx/law.c b/arch/powerpc/cpu/mpc8xxx/law.c
index b4695cc..3fd80eb 100644
--- a/arch/powerpc/cpu/mpc8xxx/law.c
+++ b/arch/powerpc/cpu/mpc8xxx/law.c
@@ -78,7 +78,7 @@
 }
 
 #if !defined(CONFIG_NAND_SPL) && \
-	(!defined(CONFIG_SPL_BUILD) || !CONFIG_IS_ENABLED(INIT_MINIMAL))
+	(!defined(CONFIG_XPL_BUILD) || !CONFIG_IS_ENABLED(INIT_MINIMAL))
 static int get_law_entry(u8 i, struct law_entry *e)
 {
 	u32 lawar;
@@ -109,7 +109,7 @@
 }
 
 #if !defined(CONFIG_NAND_SPL) && \
-	(!defined(CONFIG_SPL_BUILD) || !CONFIG_IS_ENABLED(INIT_MINIMAL))
+	(!defined(CONFIG_XPL_BUILD) || !CONFIG_IS_ENABLED(INIT_MINIMAL))
 int set_last_law(phys_addr_t addr, enum law_size sz, enum law_trgt_if id)
 {
 	u32 idx;