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/lib/crypto/Makefile b/lib/crypto/Makefile
index bec1bc9..3259c95 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -18,12 +18,12 @@
 	rsa_helper.o
 
 $(obj)/rsapubkey.asn1.o: $(obj)/rsapubkey.asn1.c $(obj)/rsapubkey.asn1.h
-ifdef CONFIG_SPL_BUILD
+ifdef CONFIG_XPL_BUILD
 CFLAGS_rsapubkey.asn1.o += -I$(obj)
 endif
 
 $(obj)/rsa_helper.o: $(obj)/rsapubkey.asn1.h
-ifdef CONFIG_SPL_BUILD
+ifdef CONFIG_XPL_BUILD
 CFLAGS_rsa_helper.o += -I$(obj)
 endif