mlxsw: Change trap groups setting

Trap groups have many options which we currently set to default values.
In the next patches we will use many of them with non-default values.

Some of these options have no default value, so this patch sets them as
params for the trap group set function. Others almost always use the same
values, so the set function will use this default values. In the rare cases
when they will need to be with other values, these values can be set
directly (using the macros for fields in registers).

Parameters without default value:
TC - the traffic class for packets that hit this trap group.
    (old default is the max tc)
priority - if one packet hits multiple trap groups, the group with the
	   higher priority will "catch" it. (old default is 0)
policer - limit rate policer (old default is disabled)

Default parameters:
swid - switch id, relevant for the emad trap only, ignored on Spectrum.
       (new default is 0)
rdq - CPU receive descriptor queue (new default is identical to trap
      group id)

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>