Cadence virtual debug interface (vdebug) integration

Change-Id: I1bc105b3addc3f34161c2356c482ff3011e3f2cc
Signed-off-by: Jacek Wuwer <jacekmw8@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6097
Tested-by: jenkins
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Reviewed-by: zapb <dev@zapb.de>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/jtag/drivers/Makefile.am

@@ -75,6 +75,9 @@ endif
 if JTAG_VPI
 DRIVERFILES += %D%/jtag_vpi.c
 endif
+if VDEBUG
+DRIVERFILES += %D%/vdebug.c
+endif
 if JTAG_DPI
 DRIVERFILES += %D%/jtag_dpi.c
 endif