integrator: rewrite the AP PCI driver

integrator: rewrite the AP PCI driver

The PCI support for the Integrator AP has apparently never
been finished and I strongly suspect that it has never worked,
so let's fix it. This is a list of the more or less
un-splittable changes done in this driver rewrite:

- Replace the register definitions stashed into the config
  file (!) with a copy if the register file from the Linux
  kernels arch/arm/include/asm/hardware/pci_v3.h

- Delete the unreadable gigantic macros that perform the
  config accesses and replace them with copyedited code from
  Linux arch/arm/mach-integrator/pci_v3.c

- Rewrite the rest of the setup code to use the
  v3_[read|write][lwb]() accessors.

- Enable PCI by default in the AP board configuration.

- Fix checkpatch warnings and make code more conformant.

Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>