Use a special signal instead of a dedicated swd mask. Amend
jtag-lock-pick_tiny_2 config accordingly.
Change-Id: Ifb007a0b5434b590c52f936efd5f5458e913e2e4
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/2183
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Tested-by: jenkins