Avoid portTICK_PERIOD_MS usage in library code

[StefanBalt]

Avoid portTICK_PERIOD_MS usage in library code

Description

portTICK_PERIOD_MS evaluates to zero when configTICK_RATE_HZ > 1000, which (while uncommon) is a valid configuration (e.g., for stress testing).

To ensure compatibility and robustness, this change replaces its usage with safer FreeRTOS-provided time conversion macros pdMS_TO_TICKS() and pdTICKS_TO_MS().

Notably, the FreeRTOS kernel itself avoids using portTICK_PERIOD_MS.

Some of the conversion code was fixed as a side effect:

• In source/FreeRTOS_DNS_Cache.c the ulCurrentTimeSeconds was not correctly converted to seconds previously, if portTICK_PERIOD_MS != 1
• In source/include/FreeRTOSIPConfigDefaults.h the portMAX_DELAY multiplication would typically overflow previously (depending on the architecure)

Test Steps

Checklist:

• I have tested my changes. No regression in existing tests.
• I have modified and/or added unit-tests to cover the code changes in this Pull Request.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[jasonpcarroll]

Hi @StefanBalt,

Thank you for this PR. I will ping someone from the team to take a look.

Best,

Jason Carroll

[tony-josi-aws]

Thanks for this PR @StefanBalt

Do you wish to update the usage of portTICK_PERIOD_MS some of the config files present in test and utilities files?

Also could you please apply the formattingChanges patch that can be found in the end of this page: https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/actions/runs/14574889771?pr=1242 to fix the formatting checks.

[StefanBalt]

Do you wish to update the usage of portTICK_PERIOD_MS some of the config files present in test and utilities files?

I will replace some of the usages.

Also could you please apply the formattingChanges

Yes, I will also format the code.