net: dsa: mv88e6xxx: do not prefix ops with g1

The mv88e6xxx_ops describe functionalities, regardless their locations
(which can be Global1, Global2, or whatever register set.)

Rename the g1_set_cpu_port and g1_set_egress_port ops to set_cpu_port
and set_egress_port. No functional changes.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>