mlx5en: Add missing media types for 100GBit/s, 200Gbit/s and 400Gbit/s.

Make the mlx5e_mode_table[] array one dimensional, because there is only
one entry, 10G ER/LR, which share the same protocol bit.

This patch only adds support for basic sub-type distinguishing for the
extended protocol bits. Use verbose ifconfig eeprom output to get actual
media type.

Remove write only "connector_type" variable while at it.

MFC after: 1 week
Reviewed by: kib
Sponsored by: Mellanox Technologies // NVIDIA Networking