net: airoha: Fix NPU RX DMA descriptor bits

net: airoha: Fix NPU RX DMA descriptor bits

In an internal review from Airoha, it was notice that the RX DMA descriptor
bits and mask are wrong. These values probably refer to an old NPU firmware
never published. The previous value works correctly but it was reported
that in some specific condition in mixed scenario with both Ethernet and
WiFi offload it's possible that RX DMA descriptor signal wrong value with
the problem to the RX ring or packets getting dropped.

To handle these specific scenario, apply the new suggested bits mask from
Airoha.

Correct functionality of both AN7581 NPU and MT7996 variant were verified
and confirmed working.

Fixes: a7fc8c641cab ("net: airoha: Fix npu rx DMA definitions")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260518134530.3683-1-ansuelsmth@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>