Initial support for BananaPi

These three commits provide support for BananaPi to uboot, linux-armv7 and linux-armv7-rc

There is an upstream known bug left, which more or less breaks ethernet support. It works only with 100Mbps and even then it's not as stable as my USB ethernet card.

And I'm still confused by all these device tables. It's booting and it's stable. Nevertheless I'm sure that some minor features are still not working (e.g status LED)