Merge branch 'selftests-forwarding-Add-new-test-cases'

Ido Schimmel says:

====================
selftests: forwarding: Add new test cases

This patchset mainly adds new forwarding test cases and performs small
changes in existing infrastructure.

Patches #1-#3 add new test cases for multicast RPF check, PCP and VLAN
matching using flower and tc VLAN modify action.

The rest of the patches are from Petr who says:

In patches #4 and #5, devlink_lib.sh is fixed to first not cause double
inclusion of lib.sh, and then to deduce the device name in a simpler way.

In patch #6, helpers for dealing with shared buffer configuration are
added to devlink_lib.sh.

In patch #7, MC-awareness test is fixed to configure shared buffers
explicitly.

In patch #8, several helpers are extracted from the MC-awareness test
and put into a new mlxsw-specific library, qos_lib.sh.

In patch #9, a new test is added which checks configuration of
strictly-prioritized streams.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>