benchmark.c: Add a mbedtls_timing_hardclock variation with xtensa CCOUNT

[yamt]

Description

benchmark.c: Add a mbedtls_timing_hardclock variation with xtensa CCOUNT

backport of Mbed-TLS/TF-PSA-Crypto#390

PR checklist

Please remove the segment/s on either side of the | symbol as appropriate, and add any relevant link/s to the end of the line.
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• changelog provided | not required because:
• development PR not required because: moved to tf-psa-crypto
• TF-PSA-Crypto PR provided benchmark.c: Add a mbedtls_timing_hardclock variation with xtensa CCOUNT TF-PSA-Crypto#390
• framework PR provided Mbed-TLS/mbedtls-framework# | not required
• 3.6 PR provided
• tests provided | not required because:

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