* Enable dynamically linked kernel. This involves adding a self-relocator

* Enable dynamically linked kernel. This involves adding a self-relocator
  to locore to process the @fptr relocations in the dynamic executable.
* Don't initialise the timer until *after* we install the timecounter to
  avoid a race between timecounter initialisation and hardclock.
* Tidy up bootinfo somewhat including adding sanity checks for when the
  kernel is loaded without a recognisable bootinfo.