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.