net: if: vlan: Implement packet priority to PCP conversion

This is actually the same as #7229 in which we missed this side of
conversion (only PCP to packet priority was implemented).

The conversion is actually the same both ways, thus it uses the map
added earlier.

Signed-off-by: Tomasz Gorochowik <tgorochowik@antmicro.com>
2 files changed