net: ipa: no checksum offload for SDM845 LAN RX

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>