[sonic-swss][202012] Update submodule (#8286)

Update submodule for swss

f54b7d0b [Dynamic Buffer Calc][202012]Bug fix: Don't create lossless buffer profile for active ports without speed configured (sonic-net/sonic-swss#1820)
ac7f5cff Td2: Reclaim buffer from unused ports (sonic-net/sonic-swss#1830)
04105a4b [debugcounterorch] check if counter type is supported before querying (sonic-net/sonic-swss#1789)
a67d8af6 [202012][portsorch] fix errors when moving port from one lag to another. (sonic-net/sonic-swss#1819)