clk: Drop duplicate selection in Kconfig

There is no need to select RATIONAL in individual drivers,
since common clock symbol does it already.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200614115140.41262-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>