Support for Centec switches

@M10 mentioned TsingMa based switches (I think in jest)

I stumbled upon the SKS8300-6Q2C after hearing about it on Reddit. 6xQSFP+ + 6xQSFP28 powered by a CTC7132 for 750 EUR / 850 USD.

They share some code on Github.

Pim van Pelt wrote about different switches build on that SoC.

Horaco joined the crowd and offers the 10G ports broken out into individual SFP+ slots. Currently on sale for less then 500 EUR

Horaco LG530S-24S2CQ and the similar looking GoodTop 530S-24S2CQ