modules: hal_nordic: adjust HFCLK ramp-up time.

Changes the ramp-up time from 1000us to 550us
on nRF54H20.
The time must fit inside general preconditions ramp up.

The hfclk time can be adjsuted this way because
the current solution is not precise until
the clock_control is available.

Signed-off-by: Piotr Koziar <piotr.koziar@nordicsemi.no>