[ARM] orion5x: added a new FPGA ID set for the TS-78xx

Stefan Agner found his board comes with 0x00b480/0x02 but the main
board also has Rev B printed on it like my 0x00b480/0x03.  Some light
enum renaming was needed but it was to be expected.

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Nicolas Pitre <nico@marvell.com>