lk/openssl: Enable x_sig compilation.

Add x_sig to compilation list.

Change-Id: If7f27eb3a445621a1f49531e6881d00bd284e63d
diff --git a/lib/openssl/crypto/rules.mk b/lib/openssl/crypto/rules.mk
index ff710c4..d149473 100644
--- a/lib/openssl/crypto/rules.mk
+++ b/lib/openssl/crypto/rules.mk
@@ -102,6 +102,7 @@
 	$(LOCAL_DIR)/asn1/x_pkey.o \
 	$(LOCAL_DIR)/asn1/x_pubkey.o \
 	$(LOCAL_DIR)/asn1/x_req.o \
+	$(LOCAL_DIR)/asn1/x_sig.o \
 	$(LOCAL_DIR)/asn1/x_spki.o \
 	$(LOCAL_DIR)/asn1/x_val.o \
 	$(LOCAL_DIR)/asn1/x_x509.o \
@@ -489,6 +490,5 @@
 Files_removed_error_during_link := \
 	$(LOCAL_DIR)/rsa/rsa_oaep.o \
 	$(LOCAL_DIR)/rsa/rsa_ssl.o \
-	$(LOCAL_DIR)/asn1/x_sig.o \
 	$(LOCAL_DIR)/bn/bn_rand.o \
 	$(LOCAL_DIR)/asn1/t_pkey.o