Add a data() function to the Matrix class to access the internal data.
This is useful for code that needs to use the matrix contents as a
linear array, as shown by the RkISP1::Ccm::process() function that needs
to copy the matrix data to a local variable. Simplify that function by
using the new accessor.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>