openocd: update 0.7.0 -> 0.8.0

* Remove unneeded --enable-<JLINK_BASED_DEBUGGER> configure flags.
  configure auto selects support for them now (and they're all enabled).

* Not everything is auto-detected; I asked on the openocd mailing list
  and they suggested a set of ./configure flags for a "distro build"
  (add them).

* Remove --enable-ft2232_libftdi because configure says that it's
  deprecated and we should use libftdi (which we are using when *not*
  passing --enable-ft2232_libftdi (or --enable-legacy-ft2232_libftdi as
  the option is now known as)).

* Add needed pkgconfig build input.

* Udev rules file has been renamed in source archive: openocd.rules =>
  99-openocd.rules.