Add a CRC module to mbedtls and baremetal config

Add a new CRC module along with some tests for it.
The table and the CRC function body is generated using pycrc v0.9.2. 
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/Makefile b/library/Makefile
index 96a9d60..f11c4df 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -99,7 +99,8 @@
 		ripemd160.o	rsa_internal.o	rsa.o  		\
 		sha1.o		sha256.o	sha512.o	\
 		threading.o	timing.o	version.o	\
-		version_features.o		xtea.o
+		version_features.o		xtea.o		\
+		crc.o
 
 OBJS_X509=	certs.o		pkcs11.o	x509.o