package/rtptools: bump to version 1.0.22

- Remove patch (already in version) and drop autoreconf
- Replace COPYRIGHT by LICENSE (and add its hash)
- License is now BSD-3-Clause:
  https://github.com/cu-irt/rtptools/commit/ed971d5e2b875294f22c0762d60aa7e409823789


- Disable clang (enabled by default)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>