net: stmmac: dwmac-rk: Add initial support for RK3528 integrated PHY

net: stmmac: dwmac-rk: Add initial support for RK3528 integrated PHY

Rockchip RK3528 (and RV1106) has a different integrated PHY compared to
the integrated PHY on RK3228/RK3328. Current powerup/down operation is
not compatible with the integrated PHY found in these newer SoCs.

Add operations to powerup/down the integrated PHY found in RK3528.
Use helpers that can be used by other GMAC variants in the future.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250319214415.3086027-6-jonas@kwiboo.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>