media: video: Stride alignment configurable by client

Prior to this patch VCAP assumed that the line stride should be
aligned to 16 bytes. It is possible that that the client needs a
line stride to be 32 bytes aligned. Line stride is now a
configurable parameter.

Change-Id: Id05aa862813582c23b18c79bd9edf95b2cdfffbe
Signed-off-by: Terence Hampson <thampson@codeaurora.org>