soc: ixp4xx: npe: Pass addresses as resources

Instead of using hardcoded base addresses implicitly
obtained through <linux/io.h>, pass the physical base
for the three NPE blocks as memory resources and remap
these in the driver.

Drop the memory request region business, this will
anyways be done by devm_* remapping functions.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>