Incorrect frequency calculation in clock period example

[vamshiKrishnaReddy20]

Description

The OpenLane2 documentation includes an example of calculating frequency from the clock period:

f = 1 / CLOCK_PERIOD = 1 / 25 ns = 25 MHz

However, the final frequency value is incorrect. Since 25 ns corresponds to 40 MHz (not 25 MHz), this example is misleading and may confuse users.

Proposal

Update the example to correctly show the frequency calculation:

f = 1 / CLOCK_PERIOD = 1 / 25 ns = 40 MHz

This correction will align the documentation with the correct physics and help users better understand clock frequency and period relationships.

[vamshiKrishnaReddy20]

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