global: Rename SPL_ to XPL_

Use XPL_ as the symbol to indicate an SPL build. This means that SPL_ is
no-longer set.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 3259c95..de1510d 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -3,16 +3,16 @@
 # Makefile for asymmetric cryptographic keys
 #
 
-obj-$(CONFIG_$(SPL_)ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o
+obj-$(CONFIG_$(XPL_)ASYMMETRIC_KEY_TYPE) += asymmetric_keys.o
 
 asymmetric_keys-y := asymmetric_type.o
 
-obj-$(CONFIG_$(SPL_)ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
+obj-$(CONFIG_$(XPL_)ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
 
 #
 # RSA public key parser
 #
-obj-$(CONFIG_$(SPL_)RSA_PUBLIC_KEY_PARSER) += rsa_public_key.o
+obj-$(CONFIG_$(XPL_)RSA_PUBLIC_KEY_PARSER) += rsa_public_key.o
 rsa_public_key-y := \
 	rsapubkey.asn1.o \
 	rsa_helper.o
@@ -30,7 +30,7 @@
 #
 # X.509 Certificate handling
 #
-obj-$(CONFIG_$(SPL_)X509_CERTIFICATE_PARSER) += x509_key_parser.o
+obj-$(CONFIG_$(XPL_)X509_CERTIFICATE_PARSER) += x509_key_parser.o
 x509_key_parser-y := \
 	x509.asn1.o \
 	x509_akid.asn1.o \
@@ -47,11 +47,11 @@
 #
 # PKCS#7 message handling
 #
-obj-$(CONFIG_$(SPL_)PKCS7_MESSAGE_PARSER) += pkcs7_message.o
+obj-$(CONFIG_$(XPL_)PKCS7_MESSAGE_PARSER) += pkcs7_message.o
 pkcs7_message-y := \
 	pkcs7.asn1.o \
 	pkcs7_parser.o
-obj-$(CONFIG_$(SPL_)PKCS7_VERIFY) += pkcs7_verify.o
+obj-$(CONFIG_$(XPL_)PKCS7_VERIFY) += pkcs7_verify.o
 
 $(obj)/pkcs7_parser.o: $(obj)/pkcs7.asn1.h
 $(obj)/pkcs7.asn1.o: $(obj)/pkcs7.asn1.c $(obj)/pkcs7.asn1.h
@@ -59,7 +59,7 @@
 #
 # Signed PE binary-wrapped key handling
 #
-obj-$(CONFIG_$(SPL_)MSCODE_PARSER) += mscode.o
+obj-$(CONFIG_$(XPL_)MSCODE_PARSER) += mscode.o
 
 mscode-y := \
 	mscode_parser.o \