[PORT FROM R2] atomisp: add CSS support for atomic ISP restart

[PORT FROM R2] atomisp: add CSS support for atomic ISP restart

BZ: 17272

This is a rework of patch 22895. The difference with that patch is that
I removed the moving of the css 3a statistics reading. This seems to cause
a strange kernel crash which seems only indirectly related to this patch.

This patch now includes:
1. Double buffering of 3A statistics inside CSS layer.
2. Functions to determine whether the next ISP binary can be
   started from an atomic context (the ISR).

Change-Id: Ic9a7a809c707d2e22ab07c4d373eea872c6132be
Orig-Change-Id: I6e633badc4f309cd8ea36548852b6fd8330daec3
Signed-off-by: Jozef Kruger <jozef.kruger@intel.com>
Reviewed-on: http://android.intel.com:8080/24166
Reviewed-by: Koski, Anttu <anttu.koski@intel.com>
Tested-by: Koski, Anttu <anttu.koski@intel.com>
Reviewed-by: Wang, Wen W <wen.w.wang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>
Reviewed-on: http://android.intel.com:8080/28015
Reviewed-by: Tuominen, TeemuX <teemux.tuominen@intel.com>