Broken links in RFSoC tutorials

[jkocz]

The links from the RFSoC regarding clocking setup/config do not seem to work.

Before proceeding briefly review the clocking information for your target platform and any additional setup/configuration required:

[ZCU216](https://casper-toolflow.readthedocs.io/projects/tutorials/en/latest/tutorials/rfsoc/platforms/zcu216.md#rf-clocking)
[ZCU208](https://casper-toolflow.readthedocs.io/projects/tutorials/en/latest/tutorials/rfsoc/platforms/zcu208.md#rf-clocking)
[ZCU111](https://casper-toolflow.readthedocs.io/projects/tutorials/en/latest/tutorials/rfsoc/platforms/zcu111.md#rf-clocking)
[RFSoC2x2](https://casper-toolflow.readthedocs.io/projects/tutorials/en/latest/tutorials/rfsoc/platforms/rfsoc2x2.md#rf-clocking)
[RFSoC4x2](https://casper-toolflow.readthedocs.io/projects/tutorials/en/latest/tutorials/rfsoc/platforms/rfsoc4x2.md#rf-clocking)
[ZRF16](https://casper-toolflow.readthedocs.io/projects/tutorials/en/latest/tutorials/rfsoc/platforms/zrf16.md#rf-clocking)

[jkocz]

Fixed by @mitchburnett.