mlxsw: Move ethtool_ops to spectrum_ethtool.c

Add spectrum_ethtool.c file for ethtool code.
Move ethtool_ops and the relevant code from spectrum.c to
spectrum_ethtool.c.

Signed-off-by: Amit Cohen <amitc@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: amitcohen1

drivers/net/ethernet/mellanox/mlxsw/Makefile

@@ -30,7 +30,8 @@ mlxsw_spectrum-objs		:= spectrum.o spectrum_buffers.o \
 				   spectrum_mr_tcam.o spectrum_mr.o \
 				   spectrum_qdisc.o spectrum_span.o \
 				   spectrum_nve.o spectrum_nve_vxlan.o \
-				   spectrum_dpipe.o spectrum_trap.o
+				   spectrum_dpipe.o spectrum_trap.o \
+				   spectrum_ethtool.o
 mlxsw_spectrum-$(CONFIG_MLXSW_SPECTRUM_DCB)	+= spectrum_dcb.o
 mlxsw_spectrum-$(CONFIG_PTP_1588_CLOCK)		+= spectrum_ptp.o
 obj-$(CONFIG_MLXSW_MINIMAL)	+= mlxsw_minimal.o