[nexthop] watchdog implementation: temporary workaround to arm 2 watchdogs

[domingo-nexthop]

Why I did it

This is a temporary workaround to arm hardware watchdog that triggers power cycle. The workaround is needed until full SW support of both watchdog 1 and 2.

Also updates the arm value to 300 seconds as this is what platform_tests
/test_hw_watchdog.py expects

Work item tracking

• Microsoft ADO (number only):

How I did it

Arm watchdog 2 by writing to 0x1d8 register before arming watchdog 1.

How to verify it

Arm watchdog using watchdogutil. sonic-mgmt test tests/platform_tests/api/test_watchdog.py

Which release branch to backport (provide reason below if selected)

• 202305
• 202311
• 202405
• 202411
• 202505
• 202511
• 202512
• 202605
• 202608

Tracking issue/work item for backport/cherry-pick request (GitHub issue or Microsoft ADO):
Failure type:

Tested branch

• master
• 202305
• 202311
• 202405
• 202411
• 202505
• 202511
• 202512
• 202605
• 202608
• N/A

Test result

sudo watchdogutil status
sudo watchdogutil arm -s 10
sudo watchdogutil status
sudo watchdogutil disarm

Description for the changelog

Link to config_db schema for YANG module changes

A picture of a cute animal (not mandatory but encouraged)

[mssonicbld]

/azp run Azure.sonic-buildimage

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[mssonicbld]

This PR has backport request for branch(es): 202512.
Added label(s) for branch(es) msft-202512.

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[mssonicbld]

This PR has backport request label(s) for branch(es): msft-202512, but is missing required test information. Please make sure you tick the tested branch(es) in the Tested branch section and provide test evidence (e.g., 202512: <test result>) in the Test result section as well in your PR description.

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[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).

[azure-pipelines]

Azure Pipelines:
There may be pipelines that require an authorized user to comment /azp run to run.

[mssonicbld]

This PR has backport request for branch(es): 202511,202512,202605.

Request label(s) for branch(es) msft-202512 already exists.
Added label(s) for branch(es) 202511,202605.

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[mssonicbld]

This PR has backport request label(s) for branch(es): 202511,202605, but is missing required test information. Please make sure you tick the tested branch(es) in the Tested branch section and provide test evidence (e.g., 202511: <test result>) in the Test result section as well in your PR description.

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[bingwang-ms]

@deerao02 Can you help review and check the fix can fix the test failure we discussed?

[deerao02]

After I applied this patch and tried on the DUT, the originally failing tests passed but it also caused some instability. The arm-cycle tests now crash the  platform_api_server. The workaround might need hardening

[mssonicbld]

Cherry-pick PR to msft-202512: Azure/sonic-buildimage-msft#2883