fm10k: fix documentation of fm10k_tlv_parse_attr

fm10k_tlv_parse_attr is supposed to return FM10K_NOT_IMPLEMENTED for any
TLV who's attribute id lies outside the range of results. It does not do
this today. In addition, the documentation does not indicate that other
attributes which are not implemented for a given TLV will be silently
ignored. Fix this. Clean up the logic so that we don't rely on the fact
that FM10K_NOT_IMPLEMENTED is greater than zero, as this can easily
cause confusion.

A future extension could look into some way of reporting unknown TLVs
in order to make issues more easily discoverable. We can't just return
FM10K_NOT_IMPLEMENTED here because we don't want to drop the entire
message if it has an unknown TLV.

While here, update the copyright year.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>