fix(versal): remove clock related macros

TF-A doesn't configure clock on Versal. Setup is done by previous
bootloader (called PLM) that's why there is no need to have macro listed in
headers. Also previous phase can disable access to these registers that's
why better to remove them.

Change-Id: I53ba344ad932c532b0babdce9d2b26e4c2c1b846
Signed-off-by: Michal Simek <michal.simek@amd.com>