irqchip/eznps: Fix build error for !ARC700 builds

eznps driver is supposed to be platform independent however it ends up
including stuff from inside arch/arc headers leading to rand config
build errors.

The quick hack to fix this (proper fix is too much chrun for non active
user-base) is to add following to nps platform agnostic header.
 - copy AUX_IENABLE from arch/arc header
 - move CTOP_AUX_IACK from arch/arc/plat-eznps/*/**

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/20200824095831.5lpkmkafelnvlpi2@linutronix.de


Signed-off-by: Vineet Gupta <vgupta@synopsys.com>