scripts: Define CONFIG_XPL_BUILD for all xPL builds

The new name 'xPL' is intended to indicate a build of any phase which is
not U-Boot proper. Define it for all such phases.

Note that we also define CONFIG_SPL_BUILD for all xPL builds. This
preserves existing behaviour, but future patches will adjust that.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/scripts/Makefile.autoconf b/scripts/Makefile.autoconf
index b42f9b5..d754402 100644
--- a/scripts/Makefile.autoconf
+++ b/scripts/Makefile.autoconf
@@ -83,15 +83,15 @@
 
 spl/u-boot.cfg: include/config.h FORCE
 	$(Q)mkdir -p $(dir $@)
-	$(call cmd,u_boot_cfg,-DCONFIG_SPL_BUILD)
+	$(call cmd,u_boot_cfg,-DCONFIG_XPL_BUILD -DCONFIG_SPL_BUILD)
 
 tpl/u-boot.cfg: include/config.h FORCE
 	$(Q)mkdir -p $(dir $@)
-	$(call cmd,u_boot_cfg,-DCONFIG_SPL_BUILD -DCONFIG_TPL_BUILD)
+	$(call cmd,u_boot_cfg,-DCONFIG_XPL_BUILD -DCONFIG_SPL_BUILD -DCONFIG_TPL_BUILD)
 
 vpl/u-boot.cfg: include/config.h FORCE
 	$(Q)mkdir -p $(dir $@)
-	$(call cmd,u_boot_cfg,-DCONFIG_SPL_BUILD -DCONFIG_VPL_BUILD)
+	$(call cmd,u_boot_cfg,-DCONFIG_XPL_BUILD -DCONFIG_SPL_BUILD -DCONFIG_VPL_BUILD)
 
 include/autoconf.mk: u-boot.cfg
 	$(call cmd,autoconf)
diff --git a/scripts/Makefile.xpl b/scripts/Makefile.xpl
index 3091311..ad21d45 100644
--- a/scripts/Makefile.xpl
+++ b/scripts/Makefile.xpl
@@ -21,15 +21,16 @@
 
 -include include/config/auto.conf
 
-# This file contains 0, 1 or 2 lines
+# This file contains 0, 2 or 3 lines
 # It is empty for U-Boot proper (where $(obj) is empty)
-# For any xPL build it contains CONFIG_SPL_BUILD=y
-# For TPL builds it has CONFIG_SPL_BUILD=y and CONFIG_TPL_BUILD=y
-# For VPL builds it has CONFIG_SPL_BUILD=y and CONFIG_VPL_BUILD=y
+# For any xPL build it contains CONFIG_SPL_BUILD=y and CONFIG_XPL_BUILD=y
+#    - for TPL builds it also contains CONFIG_TPL_BUILD=y
+#    - for VPL builds it also contains CONFIG_VPL_BUILD=y
 -include $(obj)/include/autoconf.mk
 
 UBOOTINCLUDE := -I$(obj)/include $(UBOOTINCLUDE)
 
+KBUILD_CPPFLAGS += -DCONFIG_XPL_BUILD
 KBUILD_CPPFLAGS += -DCONFIG_SPL_BUILD
 ifeq ($(CONFIG_TPL_BUILD),y)
 KBUILD_CPPFLAGS += -DCONFIG_TPL_BUILD