The fixedToFloatingPoint does not support unsigned Q types, and
incorrectly sign-extends all values which have the top most bit set in
the quantized values.
Fix this by ensuring that only signed types perform sign extension, and
simplify the calculation for unsigned types.
Convert the storage of the test cases to signed types to correctly
represent their intended purpose, to prevent test failures.
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
