[submodule] Advance sonic-sairedis pointer

Update sonic-sairedis submodule pointer to include the following:
* af80caa Add Voqs to Virtual Switch ([sonic-net#1061](sonic-net/sonic-sairedis#1061))
* f9008ad [fastboot] fastboot enhancement: Use warm-boot infrastructure for fast-boot ([sonic-net#1100](sonic-net/sonic-sairedis#1100))

Signed-off-by: dprital <drorp@nvidia.com>