GCC5 does not provide prototypes for the math library functions defined
in the math.h header for the std:: namespace.
Include the C++ <cmath> header in place of <math.h> as it defines
overloads for the std::abs and std::fmod function.
This goes intentionally against the libcamera coding guidelines, and
is reported as warning by checkpatch.py.
Fixes: 968ab9bad0 ("libcamera: ipu3: imgu: Calculate ImgU pipe configuration")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>