According to Hardware Reference Manual, OCTEON III
are mostly same as previous OCTEON models. So just
enable them and extend supported event code.
0x3e and 0x3f still reserved.

Signed-off-by: Jia Qingtong <jiaqingtong97@163.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>