Blackfin arch: change get_bf537_ether_addr() to bfin_get_ether_addr() since...

Blackfin arch: change get_bf537_ether_addr() to bfin_get_ether_addr() since this is not BF537 specific and to better match other Blackfin-specific conventions

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>