sonic-net#267)

Update sonic-linux-kernel submodule to updated 202012 branch. This brings in the following commits....

```
e97f9fc [202012] Add upstreamed patches which backport support for registers for CPLD PNs (sonic-net#275)
58abcdc Merge pull request sonic-net#267 from Staphylo/202012-log-buf-len
3f16f4f Merge pull request sonic-net#268 from Staphylo/202012-emmc-fixes
a120ae7 Apply kernel patches to fix emmc unreliability
5f4a3f3 Increase log_buf_len to 1M for all architecture
```

)

Submodule src/sonic-swss 4b489ce..90eb25d:
  > [portsorch] fix bug in speed set (sonic-net#806)

Submodule src/sonic-swss-common 2592b0c..c674e64:
  > Add multiple fields hdel support (sonic-net#267)
  > Update PFC_WD table name in CONFIG_DB (sonic-net#266)

Signed-off-by: Ying Xie <ying.xie@microsoft.com>

PFC_WD table naming change is not ready to be included yet.

Submodule src/sonic-swss-common c674e64..2592b0c (rewind):
  < Add multiple fields hdel support (sonic-net#267)
  < Update PFC_WD table name in CONFIG_DB (sonic-net#266)

Signed-off-by: Ying Xie <ying.xie@microsoft.com>

…sonic-net#2679)

Submodule src/sonic-utilities f95da07..2fe01fe:
  > neighbor advertiser script (sonic-net#469)
  > [aclshow] restore PRIO column and sort entries by priority (sonic-net#476)
  > Update watermark default polling interval to 10s (sonic-net#470)
  > show interface status <interface-name> throws error (fixes sonic-net#427) (sonic-net#440)

Submodule src/sonic-swss 90eb25d..91171b6:
  > fix a unstable swss egress acl test (sonic-net#776)
  > [aclorch] Remove  L4 port range support limitation on egress ACL table and add new SWSS virtual test. (sonic-net#741)
  > Fix orchagent SEGV when PortConfigDone not set (sonic-net#803)

Submodule src/sonic-swss-common 2592b0c..5f4abd9:
  > Force only supported commands on consumer table (sonic-net#261)
  > Add multiple fields hdel support (sonic-net#267)


Signed-off-by: Ying Xie <ying.xie@microsoft.com>