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/disk/part.c b/disk/part.c
index 706d77b..3031781 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -482,7 +482,7 @@
 	}
 #endif
 
-#if IS_ENABLED(CONFIG_CMD_UBIFS) && !IS_ENABLED(CONFIG_SPL_BUILD)
+#if IS_ENABLED(CONFIG_CMD_UBIFS) && !IS_ENABLED(CONFIG_XPL_BUILD)
 	/*
 	 * Special-case ubi, ubi goes through a mtd, rather than through
 	 * a regular block device.