clk: fractional-divider: keep mwidth and nwidth internally
The patch adds mwidth and nwidth fields to the struct clk_fractional_divider
for further usage. While here, use GENMASK() instead of open coding this
functionality.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>