staging: dpaa2-switch: export the 'no buffer' counter in ethtool

Export the DPSW_CNT_ING_NO_BUFFER_DISCARD counter in ethtool for each
switch interface. This is useful for debugging purposes.

Signed-off-by: Ionut-robert Aron <ionut-robert.aron@nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201119165017.806696-2-ciorneiioana@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>