net: stmmac: Add glue layer for T-HEAD TH1520 SoC

Add dwmac glue driver to support the DesignWare-based GMAC controllers
on the T-HEAD TH1520 SoC.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Drew Fustini <dfustini@tenstorrent.com>
Link: https://patch.msgid.link/20241103-th1520-gmac-v7-2-ef094a30169c@tenstorrent.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>