tcl/board: add Marsohod2 FPGA board config

tcl/board: add Marsohod2 FPGA board config

Marsohod2 is a very cheap FPGA Development and Education board.
Please see http://www.marsohod.org/prodmarsohod2 for details.

Sample usage:

  openocd -f board/marsohod2.cfg -c init -c "svf -tap ep3c10.tap project.svf" -c shutdown

Change-Id: Ibf39a5d463eeda9d4031fa626f01ea2599396ff2
Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Reviewed-on: http://openocd.zylin.com/2890
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-by: Paul Fertser <fercerpav@gmail.com>