[auto_negotiation] test_force_speed supports only eos fanout

[AntonHryshchuk]

Description
In change #5345, the test "test_force_speed" was changed.
Added usage of a new method for fanout "set_port_fec".
But this code added only for EOS host.

The fanout can also be the:

• OnyxHost
• AosHost
• IxiaHost

As a result, the error message from the test:

>       fanout.set_port_fec(fanout_port, fec_mode)

FEC_FOR_SPEED = {25000: 'fc', 50000: 'fc', 100000: 'rs', 200000: 'rs', ...}
dut_port   = 'Ethernet0'
........

    def __getattr__(self, module_name):
        if self.host.has_module(module_name):
            self.module_name = module_name
            self.module = getattr(self.host, module_name)
    
            return self._run
        raise AttributeError(
>           "'%s' object has no attribute '%s'" % (self.__class__, module_name)
            )
E       AttributeError: '<class 'tests.common.devices.onyx.OnyxHost'>' object has no attribute 'set_port_fec'

module_name = 'set_port_fec'

Steps to reproduce the issue:
run test "test_force_speed" on testbed with not EOS fanout

Describe the results you received:
test failure

Describe the results you expected:

[AntonHryshchuk]

@ZhaohuiS

[ZhaohuiS]

@antonptashnik Could you please take look? And the fanout could also be Sonic L2 switch.

[yxieca]

@AntonHryshchuk, @ZhaohuiS who is agreed to work on this issue?

[ZhaohuiS]

@yxieca The case was added by @antonptashnik.
@antonptashnik The case test_force_speed can only support EOS fanout, could you please enhance it to support these types of fanout as well? Thanks.
OnyxHost
AosHost
IxiaHost
SONiC L2 fanout