ARM|Driver: Add DPI Driver for emulation

ARM|Driver: Add DPI Driver for emulation

This driver provides support for Cadence JTAG BFM

The "jtag_dpi" driver implements a JTAG driver acting as a client for the
SystemVerilog Direct Programming Interface (DPI) for JTAG devices.
DPI allows OpenOCD to connect to the JTAG interface of a hardware model
written in SystemVerilog, for example, on an emulation model of
target hardware.

Tested on Ampere emulation with Altra and Altra Max models

Change-Id: Iaef8ba5cc1398ee2c888f39a606e8cb592484625
Signed-off-by: Kevin Burke <kevinb@os.amperecomputing.com>
Signed-off-by: Daniel Goehring <dgoehrin@os.amperecomputing.com>
Reviewed-on: http://openocd.zylin.com/5573
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>