MIPS: Alchemy: Fix PCI PM

Move PCI Controller PM to syscore_ops since the platform_driver PM methods
are called way too late on resume and far too early on suspend (after and
before PCI device resume/suspend).
This also allows to simplify wired entry management a bit.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3007/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>