net: stmmac: dwmac-qcom-ethqos: Fix drops in 10M SGMII RX

In 10M SGMII mode all the packets are being dropped due to wrong Rx clock.
SGMII 10MBPS mode needs RX clock divider programmed to avoid drops in Rx.
Update configure SGMII function with Rx clk divider programming.

Fixes: 463120c3

 ("net: stmmac: dwmac-qcom-ethqos: add support for SGMII")
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Sneh Shah <quic_snehshah@quicinc.com>
Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Link: https://lore.kernel.org/r/20231212092208.22393-1-quic_snehshah@quicinc.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>