soc: ixp4xx: qmgr: Pass resources

Instead of using hardcoded base address implicitly
obtained through <linux/io.h>, pass the physical base
for the QMGR block as a memory resource and remap
it in the driver.

Also pass the two IRQs as resources and obtain them
in the driver.

Use devm_* accessors and simplify the error path in the
process. Drop memory region request as this is done by
the devm_ioremap* functions.

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