[submodule][master] Update submodule sonic-stp to the latest HEAD automatically

[mssonicbld]

Why I did it

src/sonic-stp

* 29eb387 - (HEAD -> master, origin/master, origin/HEAD) Fixing compilaion error for marvell_armhf (#47) (9 hours ago) [Divya Kumaran Chandralekha]
*   b7da558 - Merge pull request #44 from wajahatrazi/stp_co_pr (3 days ago) [Divya Kumaran Chandralekha]
|\  
| *   47e1e77 - Merge branch 'master' into stp_co_pr (3 days ago) [Divya Kumaran Chandralekha]
| |\  
| |/  
|/|   
* |   6e4a94f - Merge pull request #46 from divyachandralekha/pvst_pr_1 (4 days ago) [Divya Kumaran Chandralekha]
|\ \  
| * | aa5e824 - libevent explicit building dependency removed (4 days ago) [Divya Chandralekha]
|/ /  
* | 9345e5a - Merge pull request #43 from omaaartamer/fix/alignment-warnings (5 days ago) [Divya Kumaran Chandralekha]
* | eedb772 - [stp] Add memory alignment padding to structures (9 weeks ago) [omaaartamer]
* | 128e53d - fix: resolve STP alignment warnings (9 weeks ago) [omaaartamer]
 /  
* 30febfa - Fixing changes in the code (9 weeks ago) [Wajahat Razi]

How I did it

How to verify it

Description for the changelog

[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mssonicbld]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).