Add a disable sub-command to the cpu command that allows for disabling
cores in multicore processors.  This can be useful for systems that are
using multicore chips but aren't utilizing all the cores as a way to
reduce power and possibly improve performance.

Also updated an added missing copyright.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

* Use CONFIG_MP instead of CONFIG_NUM_CPUS to match 85xx
* Introduce determine_mp_bootpg() helper.  We'll need this to address a
  bug introduced in v2009.03 with 86xx MP booting.  We have to make sure
  to reserve the region of memory used for the MP bootpg() so other
  u-boot code doesn't use it.
* Added dummy versions of cpu_reset(), cpu_status() & cpu_release() to
  allow cmd_mp.c to build and work. In the future we should look at
  implementing all these functions. This could be common w/85xx if we
  use spin tables on 86xx.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

We put the bootpg for the secondary cpus into memory and use
BPTR to get to it.  This is a step towards converting to the
ePAPR boot methodology.  Also, the code is written to
deal properly with more than 4GB of RAM.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>