[submodule] Update submodule sonic-linux-kernel to the latest HEAD au…

…tomatically (sonic-net#19367)

#### Why I did it
src/sonic-linux-kernel
```
* a128c86 - (HEAD -> master, origin/master, origin/HEAD) Add DesignWare PCI Core Support for AMD Ryzen Embedded processors (sonic-net#395) (4 days ago) [Roger Ho]
```
#### How I did it
#### How to verify it
#### Description for the changelog