atl1c: remove multiple-RX-Q code

the multiple-RX-Q in hardware doesn't work,
all related register definition & code are removed.

Signed-off-by: xiong <xiong@qca.qualcomm.com>
Tested-by: Liu David <dwliu@qca.qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>