net: ethernet: mediatek: Rename MTK_QMTK_INT_STATUS to MTK_QDMA_INT_STATUS

Currently all QDMA registers are named "MTK_QDMA_foo" in this driver
with one exception: MTK_QMTK_INT_STATUS. This patch renames
MTK_QMTK_INT_STATUS to MTK_QDMA_INT_STATUS so that all macros follow
this rule.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: René van Dorst <opensource@vdorst.com>
Cc: Daniel Golle <daniel@makrotopia.org>
Cc: Sean Wang <sean.wang@mediatek.com>
Cc: John Crispin <john@phrozen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>