net: stmmac: do not stop RX_CLK in Rx LPI state for qcs404 SoC

Currently in phy_init_eee() the driver unconditionally configures the PHY
to stop RX_CLK after entering Rx LPI state. This causes an LPI interrupt
storm on my qcs404-base board.

Change the PHY initialization so that for "qcom,qcs404-ethqos" compatible
device RX_CLK continues to run even in Rx LPI state.

Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>