[CI] Resolve #1357 - Use cmp_pcm instead of check_BE in split rendering tests

• Related issues: #1357 (closed)
• Requested reviewers: @tamarapu @tyagiri

Reason why this change is needed

• check_BE silently ignores delay differences <= 20ms which can mask non-BE results

Description of the change

• Apply comparison with cmp_pcm.py (like all of the other tests do). That one does not do any delay compensation

Affected operating points

• Tests only

Related to #1357 (closed)