psa: Add TF-M utility scripts to python path

When python3 is enforced to build the ARM_MUSCA_A1 or ARM_MUSCA_B1
targets, it is unable to find binary utility tool scripts which are
imported from TF-M.

The reason to use the python3 environment is as follows: Mbed OS + TFM
contained a faulty boot record TLV, which failed the attestation test
(TF-M regression). The data in the boot record TLV will be included in
the generated attestation token as 1 item in the SW_COMPONENTS claim.

This data (in the boot record TLV) is pre-encoded in CBOR format at
build time and appended to the image during the image signing process
(done by the imgtool Python3 script).

Signed-off-by: Vikas Katariya <vikas.katariya@arm.com>

tools/targets/__init__.py

@@ -22,6 +22,7 @@ import struct
 import shutil
 import inspect
 import sys
+
 from collections import namedtuple
 from copy import copy
 from future.utils import raise_from
@@ -31,6 +32,11 @@ from tools.paths import TOOLS_BOOTLOADERS
 from tools.utils import json_file_to_dict, NotSupportedException
 from tools.psa import find_secure_image
 
+# Add PSA TF-M binary utility scripts in system path
+from os.path import dirname, abspath, join
+TFM_SCRIPTS = abspath(join(dirname(__file__), '..', 'psa', 'tfm', 'bin_utils'))
+sys.path.insert(0, TFM_SCRIPTS)
+
 
 __all__ = ["target", "TARGETS", "TARGET_MAP", "TARGET_NAMES", "CORE_LABELS",
            "CORE_ARCH", "HookError", "generate_py_target", "Target",