math.h: Introduce data types for fractional numbers

Introduce a macro to produce data types like

	struct TYPE_fract {
		__TYPE numerator;
		__TYPE denominator;
	};

to be used in the code wherever it's needed.

In the following changes convert some users to it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220126135353.24007-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>