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/common/Makefile b/common/Makefile
index c52d4c3..ae89846 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -4,7 +4,7 @@
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 
 # core
-ifndef CONFIG_SPL_BUILD
+ifndef CONFIG_XPL_BUILD
 obj-y += init/
 obj-y += main.o
 obj-y += exports.o
@@ -42,12 +42,12 @@
 obj-$(CONFIG_UPDATE_COMMON) += update.o
 obj-$(CONFIG_USB_KEYBOARD) += usb_kbd.o
 
-endif # !CONFIG_SPL_BUILD
+endif # !CONFIG_XPL_BUILD
 
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTAGE) += bootstage.o
 obj-$(CONFIG_$(SPL_TPL_)BLOBLIST) += bloblist.o
 
-ifdef CONFIG_SPL_BUILD
+ifdef CONFIG_XPL_BUILD
 ifdef CONFIG_SPL_DFU
 obj-$(CONFIG_DFU_OVER_USB) += dfu.o
 endif
@@ -58,7 +58,7 @@
 obj-$(CONFIG_SPL_MUSB_NEW) += usb.o
 obj-$(CONFIG_SPL_SPLASH_SCREEN) += splash.o
 obj-$(CONFIG_SPL_SPLASH_SOURCE) += splash_source.o
-endif # CONFIG_SPL_BUILD
+endif # CONFIG_XPL_BUILD
 
 #others
 obj-$(CONFIG_DDR_SPD) += ddr_spd.o