Add JTAG connector

[xcancerberox]

The JTAG is accessible on expose IOs connector. Will be more easy if it is a separated connector.

Connector 2x5 din will be added with JTAGice MkII layout:

[xcancerberox]

There is a jtag header for mips microprocessors

https://www.linux-mips.org/wiki/JTAG

Will change the connector pinout to be compliant with this.

1 nTRST (not present, a pad will be left for future hacks)
2 GND
3 TDI
4 GND
5 TDO
6 GND
7 TMS
8 GND
9 TCK
10 GND
11 nSRST
12 -key (not used)
13 DINT (not used)
14 VCC