drivers: clock_control: ra: fix initialization of the clock_hw_cycles

We should set the z_clock_hw_cycles_per_sec as the value of
the system clock frequency.

There was a mistake in referencing the clock source set before
initialization.
I corrected it to reflect the clock value after initialization.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@fujitsu.com>
1 file changed