global: Use CONFIG_XPL_BUILD instead of CONFIG_SPL_BUILD

Complete this rename for all directories outside arch/ board/ drivers/
and include/

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/test/test-main.c b/test/test-main.c
index b3d3e24..479dbb3 100644
--- a/test/test-main.c
+++ b/test/test-main.c
@@ -47,7 +47,7 @@
 static enum fdtchk_t fdt_action(void)
 {
 	/* For sandbox SPL builds, do nothing */
-	if (IS_ENABLED(CONFIG_SANDBOX) && IS_ENABLED(CONFIG_SPL_BUILD))
+	if (IS_ENABLED(CONFIG_SANDBOX) && IS_ENABLED(CONFIG_XPL_BUILD))
 		return FDTCHK_NONE;
 
 	/* Do a copy for sandbox (but only the U-Boot build, not SPL) */