dpaa2-eth: fix misspelled function parameters in dpni_[set/get]_taildrop

Two of the function parameters (qtype and index) were misspelled in the
associated descriptions of dpni_[set/get]_taildrop which led to sparse
warnings. Fix this by using the exact same names as present in the
function definition.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>