net: stmmac: dwmac-qcom-ethqos: fix error array size

Correct member @num_por with size of right array @emac_v4_0_0_por for
struct ethqos_emac_driver_data @emac_v4_0_0_data.

Cc: stable@vger.kernel.org
Fixes: 8c4d92e8

 ("net: stmmac: dwmac-qcom-ethqos: add support for emac4 on sa8775p platforms")
Signed-off-by: Yijie Yang <quic_yijiyang@quicinc.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://patch.msgid.link/20240701014720.2547856-1-quic_yijiyang@quicinc.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>