dtb/allwinner: Restore a83t/BananaPi-M3 DTS after r342822

sinovoip-bpi-m3.dts was disconnected from the build in r324822. Since then,
a CCU driver has been added and several other changes have been made to
make us compatible with upstream DTS for this board.

Add links for older DTB that might be used: our u-boot port was expecting
sinovoip-bpi-m3.dtb up until ports r455629, and our u-boot will not be
switching to the upstream name (sun8i-a83t-bananapi-m3) quite yet.

Discussed with: manu