brcm47xx: update tg3 to the version send upstream


git-svn-id: svn://svn.openwrt.org/openwrt@35573 3c298f89-4303-0410-b956-a3cf2f4a3e73
brcm47xx: add some more fixes to bgmac

Thank you Rafał Miłecki and Nathan Hintz


git-svn-id: svn://svn.openwrt.org/openwrt@35574 3c298f89-4303-0410-b956-a3cf2f4a3e73