[RFC/PATCH] tlv/msgb: Be able to generate and parse TLV as used by LLDP

Hi! we have the need to generate and parse LLDP frames and would like to use the TLV infrastructure of libosmocore for it. In LLDP the tag is only 7bit and the length is 9bit long. To make this work with the tlv parsing routines we need to shift the tag. But this means that when somebody is a tlv_definition with the T7L9 type and others we might match the wrong thing. I would like to include the feature as it is right now. The alternative would be to create a separate tlv_parse and tlv_parse_one routine for the other type. comments? holger