We already have Designware NIC support in barebox, but for the DWMAC1000,
the DWMAC4 (also called GMAC4), no support was mainline so far.
The DWMAC4 is different enough that sharing code with the DWMAC1000 is
not really that helpful, because even basics like MDIO registers have
different layout. Instead of coding bit masks and shifts into the driver
data, like Linux does, we'll keep both driver kinds separate.
Nevertheless, we collect functions that are not SoC-specific into a
separate 'library' file.
Signed-off-by: Ahmad Fatoum <firstname.lastname@example.org>
Signed-off-by: Sascha Hauer <email@example.com>