libgralloc: Add Perform function to get the stride.

- Introduce a new class to Get the Adreno computed stride information.
This class has been added to allow adreno library computed strides to
be propagated to the allocation function as well as those clients
requesting it.
- Add a new Perform function to get the stride. The width and the format
can be passed from the calling functions (like EGL) to get the stride of
the buffer.

Change-Id: I4c2b4a02deff327f0ea5558c478997527fe9d3cf
4 files changed