staging: bcm2835-camera: Convert struct mmal_buffer_header info fields to u32

The struct mmal_buffer_header has multiple fields used for informational
and debugging purposes.  These are safe to convert to u32.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>