net/mlx5: control flow rules with identical pattern

net/mlx5: control flow rules with identical pattern

In order to allow\disallow configuring rules with identical
patterns, the new device argument 'allow_duplicate_pattern'
is introduced.
If allow, these rules be inserted successfully and only the
first rule take affect.
If disallow, the first rule will be inserted and other rules
be rejected.

The default is to allow.
Set it to 0 if disallow, for example:
	-a <PCI_BDF>,allow_duplicate_pattern=0

Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>