Android-IA: Add support to easily add new formats.

Android-IA: Add support to easily add new formats.

Camera, Media use cases seem to need lot of custom
formats depending on hardware support. This patch
squashes earlies work done for NV12, NV12 tiled etc
into one and also makes it easy to isolate these
custom formats into i915_private_* files, rather
than spreading them over whole code base.

Signed-off-by: Harish Krupo <harish.krupo.kps@intel.com>
Signed-off-by: Jeevaka Prabu Badrappan <jeevaka.badrappan@intel.com>
Signed-off-by: Yaodong Li <yaodong.li@intel.com>
Signed-off-by: Kalyan Kondapally <kalyan.kondapally@intel.com>
Signed-off-by: Lin Johnson <lin.johnson@intel.com>
Signed-off-by: Yin Zhiye <zhiyex.yin@intel.com>