KEYS: Add a name for PKEY_ID_PKCS7

Add a name for PKEY_ID_PKCS7 into the pkey_id_type_name array.

Signed-off-by: David Howells <[e-mail]>

crypto/asymmetric_keys/public_key.c

···
 const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
 	[PKEY_ID_PGP]		= "PGP",
 	[PKEY_ID_X509]		= "X509",
+	[PKEY_ID_PKCS7]		= "PKCS#7",
 };
 EXPORT_SYMBOL_GPL(pkey_id_type_name);