net: mvpp2: parser fix QinQ

The mvpp2 parser entry for QinQ has the inner and outer VLAN
in the wrong order.
Fix the problem by swapping them.

Fixes: 3f518509

 ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Reviewed-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>