net: stmmac: Add support for Allwinner A523 GMAC200

The Allwinner A523 SoC family has a second Ethernet controller, called
the GMAC200 in the BSP and T527 datasheet, and referred to as GMAC1 for
numbering. This controller, according to BSP sources, is fully
compatible with a slightly newer version of the Synopsys DWMAC core.
The glue layer around the controller is the same as found around older
DWMAC cores on Allwinner SoCs. The only slight difference is that since
this is the second controller on the SoC, the register for the clock
delay controls is at a different offset. Last, the integration includes
a dedicated clock gate for the memory bus and the whole thing is put in
a separately controllable power domain.

Add a new driver for this hardware supporting the integration layer.

Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250925191600.3306595-3-wens@kernel.org


Signed-off-by: Paolo Abeni <pabeni@redhat.com>