The b53 driver was added as a dsa driver into the mainline Linux kernel,
but we still use the swconfig based driver. The header file b53.h is
used by both drivers, but the swconfig one needs an extra member, add
this one in a patch to not overwrite the version shipped with the
mainline kernel.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>