Improve mutex locking protection for concurrent thread usage

[dgarske]

Use a global mutex instead of one that is part of TPM2_CTX. ZD 19771
Add build option WOLFTPM_NO_ACTIVE_THREAD_LS to support no thread local on gActiveTPM.

[Copilot]

Pull Request Overview

This PR improves mutex locking protection for concurrent thread usage by replacing per-context locks with a global lock and adds a build option to support configurations without thread local storage for the active TPM2_CTX.

• Removed TPM2_CTX-specific mutex and lock count fields in favor of a global mutex.
• Introduced fallback macros in tpm2_types.h for older wolfSSL versions.
• Updated lock acquisition/release logic in src/tpm2.c to use the global gHwLock and conditionally initialize/free it.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
wolftpm/tpm2_types.h	Added fallback definitions for mutex initializer macros to support older wolfSSL.
wolftpm/tpm2.h	Removed per-instance mutex and lock count from TPM2_CTX to use a global mutex.
src/tpm2.c	Refactored lock functions to use the global gHwLock and updated active context support.

[embhorn]

TPM2_AcquireLock is so much cleaner. Looks great.