ima: define kernel parameter 'ima_template=' to change configured default

This patch allows users to specify from the kernel command line the
template descriptor, among those defined, that will be used to generate
and display measurement entries. If an user specifies a wrong template,
IMA reverts to the template descriptor set in the kernel configuration.

Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 1a036cd9..2b78cb5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1190,6 +1190,11 @@
 			programs exec'd, files mmap'd for exec, and all files
 			opened for read by uid=0.
 
+	ima_template=   [IMA]
+			Select one of defined IMA measurements template formats.
+			Formats: { "ima" | "ima-ng" }
+			Default: "ima-ng"
+
 	init=		[KNL]
 			Format: <full_path>
 			Run specified binary instead of /sbin/init as init