[Pach][imx-code-signing-tool] hab_csf_parser: improve IVT header search

[Eximius]

Hello,

please see the attached patch for cst-3.4.1.

- Images with appended CSF might have coincidentally the IVT
pattern (IVT_HDR_VAL) before the actual CSF.

- This changes the search by checking if the CSF in the IVT is
within boundaries and has a valid HAB_TAG_CSF or else it will
continue searching for the IVT pattern.

I hope this can be submitted here. Otherwise please inform me where to send the patch to. Thanks.

Regards,
Ian

[Eximius]

v3 fixes a segfault when debug log is deactivated

[Chavira · Accepted solution]

Hi @Eximius!

Thank you for sharing your improvements.
Your contributions are truly appreciated by both NXP and the community.

Best regards,
Chavira