ti: k3: common: Set L2 latency on A72 cores

The Cortex-A72 based cores on K3 platforms can be clocked fast
enough that an extra latency cycle is needed to ensure correct
L2 access. Set the latency here for all A72 cores.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Change-Id: Id534316dec1c1f326908efbfd964f219cda7386a