cryptfs-tpm2: convert the script to python3

Convert the script to python3 to fix the do_compile failure.

Fixes:
/buildarea/poky/build/tmp/work/core2-64-poky-linux/cryptfs-tpm2/0.7.0+gitAUTOINC+888c46c827-r0/git/scripts/encrypt_secret.py -i "H31i05" > "primary_key.secret" || exit 1
/usr/bin/env: ‘python’: No such file or directory
Makefile:64: recipe for target 'primary_key.secret' failed

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>

meta-encrypted-storage/recipes-tpm/cryptfs-tpm2/cryptfs-tpm2/0001-encrypt_secret.py-switch-to-python3.patch

@@ -0,0 +1,32 @@
+From 480648bd9a516fc84b02d0b83ebccf40547e5dd0 Mon Sep 17 00:00:00 2001
+From: Yi Zhao <yi.zhao@windriver.com>
+Date: Fri, 13 Mar 2020 20:17:46 +0800
+Subject: [PATCH] encrypt_secret.py: switch to python3
+
+Upstream-Status: Submitted [https://github.com/jiazhang0/cryptfs-tpm2/pull/7]
+
+Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
+---
+ scripts/encrypt_secret.py.in | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+diff --git a/scripts/encrypt_secret.py.in b/scripts/encrypt_secret.py.in
+index 1ddb76d..ffd3213 100755
+--- a/scripts/encrypt_secret.py.in
++++ b/scripts/encrypt_secret.py.in
+@@ -1,11 +1,10 @@
+-#!/usr/bin/env python
++#!/usr/bin/env python3
+ #coding: UTF-8
+ 
+ '''
+ The simple encryption/decryption for secret info
+ '''
+ 
+-from __future__ import print_function
+ import logging
+ import argparse
+ import struct
+-- 
+2.7.4
+

meta-encrypted-storage/recipes-tpm/cryptfs-tpm2/cryptfs-tpm2_git.bb

@@ -22,6 +22,7 @@ PV = "0.7.0+git${SRCPV}"
 SRC_URI = "\
     git://github.com/jiazhang0/cryptfs-tpm2.git \
     file://0001-luks-setup.sh-Add-support-for-qemu-with-the-swtpm.patch \
+    file://0001-encrypt_secret.py-switch-to-python3.patch \
 "
 SRCREV = "87c35c63090a33d4de437f518b8da9f2d1f1d828"