[submodule]: update sonic-platform-common (#8178)

* 063e915 2021-06-15 | [CI] sonic-config-engine now depends on SONiC YANG packages (#198) (HEAD, origin/202012) [Joe LeVeque]
* 2d36a79 2021-07-13 | Fix Xcvrd crash due to invalid key access in type_of_media_interface, host_electrical_interface, connector_dict (#206) [Prince George]
* 67b8a77 2021-06-18 | Fix decode error when parsing EEPROM fields (#199) [Aravind Mani]
* 238d76b 2021-06-17 | Unifying the platform api for get_pcie_aer_stats with PcieBase (#197) [Sujin Kang]

Signed-off-by: Guohan Lu <lguohan@gmail.com>