Add Support for 32-bit ARCv3 HS Processors (HS56, HS57D, HS58) to OpenOCD

[abrodkin]

We would like to upstream support for 32-bit ARCv3 HS processors (ARC HS5x family: HS56, HS57D, HS58) to the main OpenOCD repository. This support has already been implemented and validated internally by Synopsys engineers and is available in our downstream fork here: https://github.com/foss-for-synopsys-dwc-arc-processors/openocd/tree/arcv3-master

The implementation consists of two commits:

1. foss-for-synopsys-dwc-arc-processors/openocd@0fbbfca
2. foss-for-synopsys-dwc-arc-processors/openocd@87187af

This issue is being filed for tracking purposes. Our goal is to make this functionality available to the wider community as part of the next official OpenOCD release, rather than keeping it maintained solely in our fork.

For the record, once configured and built (./configure --enable-ftdi --disable-doxygen-html && make), one may start it in the following way:

./src/openocd -s ./tcl -f ./tcl/board/snps_hs5_fpga.cfg

Note though, snps_hs5_fpga.cfg is for a single-core ARC HS5x.