This patch adds the management of (almost) all the config options of
openocd 0.8.0. A BR config variable is added for (almost) every
adapter known to openocd and all the dependencies are automatically
calculated from the chosen adapters, so only the necessary libraries
are built.
Note that CMSIS_DAP adapter requires hidapi (not libhid) and hidapi is
not actually included in buildroot, so it has been removed. Also
zy1000 adapters are actually broken in openocd and have been removed.
The host version of the package enables all the possible adapters and
the related libraries.