Update log level for mbedtls_ssl_check_record and PSA-based ECDH computation (3.6)

[JuhaPekkaa]

Description

I noticed some logs that are logged as errors that are not actually indicative of serious issues.
I also asked about it on the discord server.

According to the debug.h, informational logs should be of log level 3.

Our implementation translates mbedlts logs from 1 to WARN.
The following logs are set at level 1, but they do not signify that an error has occurred.

WARN [mbedtls ssl_msg.c:366] <= mbedtls_ssl_check_record
WARN [mbedtls ssl_msg.c:324] => mbedtls_ssl_check_record 

WARN  [mbedtls ssl_tls12_client.c:2307] Perform PSA-based ECDH computation.
WARN  [mbedtls ssl_tls12_server.c:2686] Perform PSA-based ECDH computation.

PR checklist

• changelog not required?
• development PR | Update log level for mbedtls_ssl_check_record and PSA-based ECDH computation #10496
• TF-PSA-Crypto PR not required.
• framework PR not required.
• 3.6 PR This PR.
• tests not required.

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[gilles-peskine-arm]

LGTM

[davidhorstmann-arm]

LGTM, thanks!