bsp, hil: flash with the unified OpenOCD fork
https://github.com/hathach/openocd (branch tinyusb) is mainline plus every
config these boards need: RPi RP2350, ADI max32/max78, the MounRiver WCH
configs, and the wlinke adapter on mainline's riscv target. It is a superset
of the vendor forks, so one 'openocd' covers all boards; -DOPENOCD=/OPENOCD=
still select another, msdk's when MAXIM_PATH is set.
Drops family_flash_openocd_wch and the OPENOCD_WCH pair, dedups
family_flash_openocd_adi, aligns ch583's work area, and points hil at the
flasher's own config instead of generating one per probe.
Verified: HIL green on all four WCH boards and max32666fthr.
1d915b6b59