[POWERPC] mpc82xx: Update mpc8272ads, and factor out PCI and reset.

1. PCI and reset are factored out into pq2.c.  I renamed them from m82xx
to pq2 because they won't work on the Integrated Host Processor line of
82xx chips (i.e. 8240, 8245, and such).

2. The PCI PIC, which is nominally board-specific, is used on multiple
boards, and thus is used into pq2ads-pci-pic.c.

3. The new CPM binding is used.

4. General cleanup.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>