Modularized adsp, cdsp, and wpss remoteproc tests using common helper functions

[Sai-teja573]

Refactored remoteproc test scripts for adsp, cdsp, and wpss to use modular helper functions from functestlib.sh.

Changes include:

• Replaced hardcoded logic with reusable functions: get_remoteproc_path_by_firmware, get_remoteproc_state, stop_remoteproc, and start_remoteproc.
• Improved readability, maintainability, and consistency across these subsystem tests.

This modularization lays the foundation for extending the same structure to other subsystems like gdsp and general remoteproc validation in future updates.

[smuppand]

A few changes are needed to make it more CI-friendly and easier to debug failures.

[Sai-teja573]

Added a check to verify if the firmware is loaded when the remoteproc is not running, as suggested.
I'm using dmesg | grep -i "Booting fw image" | grep -i "$name" to confirm firmware load status, which provides better visibility during CI/debugging.

[smuppand]

A few additional minor changes are still required.

[smuppand]

A few minor adjustments are needed to ensure better consistency with the logging standards.

[vnarapar]

Please remove this