Add wchisp for additional upload method

[hathach]

This PR add wchisp as tool dependency. This is used as additional upload method with ch32 bootrom in openwch/arduino_core_ch32#129. The binary from wchisp release page can be used directly with Arduino json (we make a couple PR to wchisp to make it compatible with arduino IDE).

Once this is merged when releasing an new version e.g 1.0.5, we need to include this to toolsDependencies list.

            {
              "packager": "WCH",
              "name": "wchisp",
              "version": "0.2.3"
            }

Let me know if this makes sense to you.

@ladyada

[ladyada]

i tested this and it works very well