include: 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/include/mmc.h b/include/mmc.h
index f508cd1..61d1f4b 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -725,7 +725,7 @@
 	u64 capacity_boot;
 	u64 capacity_rpmb;
 	u64 capacity_gp[4];
-#ifndef CONFIG_SPL_BUILD
+#ifndef CONFIG_XPL_BUILD
 	u64 enh_user_start;
 	u64 enh_user_size;
 #endif