net: dwc_eth_qos_rockchip: Add support for RK3588

net: dwc_eth_qos_rockchip: Add support for RK3588

Add rk_gmac_ops and other special handling that is needed for GMAC to
work on RK3588.

rk_gmac_ops was ported from linux commits:
2f2b60a0ec28 ("net: ethernet: stmmac: dwmac-rk: Add gmac support for rk3588")
88619e77b33d ("net: stmmac: rk3588: Allow multiple gmac controller")

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>