[submodule] Update submodule sonic-bmp to the latest HEAD automatical…

…ly (sonic-net#20847)

#### Why I did it
src/sonic-bmp
```
* bfbd47b - (HEAD -> master, origin/master, origin/HEAD) Merge pull request #15 from FengPan-Frank/makefile (13 hours ago) [Feng-msft]
* ad31f5b - Create makefile for build image flow (17 hours ago) [Feng Pan]
```
#### How I did it
#### How to verify it
#### Description for the changelog