board: arc: hsdk*: Accommodate upstream OpenOCD for ARC

During review of ARC port of OpenOCD some changes were requested
in particular:
1. L2 cache (SLC in ARC parlance) semantics, see
   http://openocd.zylin.com/#/c/5688/

2. JTAG probe interface (AKA "adapter") setup, see
   http://openocd.zylin.com/#/c/5784/



And so we need to change OpenOCD scripts accordingly to match
newer OpenOCD version from Zephyr's SDK v0.12.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>