msm: vidc: add NV12 multi-view top-bottom color definition

H.264 MVC codec provides a NV12 color format output with
top-bottom layout, this is not consider as a new color
format by the firmware or driver. The change provides the
definition and helper functions to handle this layout.

Change-Id: I008d772c52e145214c95c3a0f673955cd7cdb33e
Signed-off-by: Jorge Solano Altamirano <jsolano@codeaurora.org>