The AP LAN RX endpoint should not have download checksum offload
enabled.

The receive handler does properly accommodate the trailer that's
added by the hardware, but we ignore it.

Fixes: 1ed7d0c0 ("soc: qcom: ipa: configuration data")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>