[TF-M] TF-M v1.6.1 hotfix release

Hi,

TF-M released a hotfix to the current version, tagged by TF-Mv1.6.1https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/tag/?h=TF-Mv1.6.1.

The fixes:

* Correctly apply the stack sealing for the PSP stack in library mode * Fix an issue by which the TF-M Crypto service might use invalid lengths for output buffer parameters for some PSA Crypto APIs calls leading to an automatic reset of the device when the API should just return PSA_ERROR_BUFFER_TOO_SMALL

Please do not confuse it with the upcoming main release v1.7.0 planned for the beginning of December.

Thanks, Anton