Alphascale asm9260 has similar functionality but different register
offsets. To support asm9260 in the mxs driver we need to rework the
hardcoded access mechanisms.

- Define SET_REG and CLR_REG. These controllers support seperate CLR and
  SET offsets for each register.

- Reimplement HW_ICOLL_INTERRUPT with SET_REG and CLR_REG to make it
  usable for both cases.

- Instead of using icoll_base and adding the offsets at runtime,
  create a new data structure which contains base pointers to all
  required regitsters and use it.

- Split out functionality, which is required for the init code of mxs
  and asm9260, into helper functions

[ tglx: Massaged changelog and moved the return value change to the
  	previous patch ]
Signed-off-by: NOleksij Rempel <linux@rempel-privat.de>
Tested-by: NShawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: marc.zyngier@arm.com
Cc: jason@lakedaemon.net
Link: http://lkml.kernel.org/r/1444677334-12242-5-git-send-email-linux@rempel-privat.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>