sunxi: bring up DSA b53 switch on Lamobo R1
Build cortexa7 subtarget with DSA driver for MDIO-connected Broadcom
BCM53xxx switches. This is needed for the Lamobo R1 aka. BananaPi
BPi-R1 board which comes with such a switch IC.
Remove old swconfig driver from target kernel config as the only board
using it is now supported by the DSA driver.
No changes to device tree are needed as upstream DTS already got a
DSA switch definition and we are just using that upstream source.
Update default network config of the Lamobo R1 to create lan bridge
with all 4 lan ports.
Introduce DEVICE_COMPAT_VERSION for the board to inform users about
having the re-create their network configuration and add device alias
as Bananapi BPi-R1 while at it.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>