PKCS#7: Add MODULE_LICENSE() to test module

Add a MODULE_LICENSE() line to the PKCS#7 test key module to fix this
warning:

	WARNING: modpost: missing MODULE_LICENSE() in
	crypto/asymmetric_keys/pkcs7_test_key.o

Whilst we're at it, also add a module description.
Reported-by: James Morris <jmorris@namei.org>
Signed-off-by: David Howells <dhowells@redhat.com>

crypto/asymmetric_keys/pkcs7_key_type.c

@@ -20,6 +20,9 @@
 #include <keys/system_keyring.h>
 #include "pkcs7_parser.h"
 
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("PKCS#7 testing key type");
+
 static unsigned pkcs7_usage;
 module_param_named(usage, pkcs7_usage, uint, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(pkcs7_usage,