ARM: integrator: Convert PCI to use generic config accessors

Convert the integrator PCI driver to use the generic config access
functions.

This changes accesses from __raw_readX/__raw_writeX to readX/writeX
variants.  The spinlock is removed because it is unnecessary.  The config
read and write functions are already protected with a spinlock and no
access can occur during the .pre_init function.

[arnd: remove unused "flags"]
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
CC: Russell King <linux@arm.linux.org.uk>
CC: linux-arm-kernel@lists.infradead.org