[202012][submodule] Update swss pointer (#8782)

* c3691d3 [202012][pfcwd] Convert polling interval from ms to us in LUA scripts (#1909)
* 549c804 Mux state order change (#1902)
* 6b0b2c4 Update acl type check logic (#1886)

Signed-off-by: Volodymyr Samotiy <[email protected]>

Author: volodymyrsamotiy