[submodule] Update submodule sonic-linux-kernel to the latest HEAD automatically (#16757)

#### Why I did it
src/sonic-linux-kernel
```
* ecba611 - (HEAD -> master, origin/master, origin/HEAD) arm64: Enable CONFIG_KEXEC_FILE (#333) (6 hours ago) [pavannaregundi]
```
#### How I did it
#### How to verify it
#### Description for the changelog

Author: mssonicbld