ti: k3: common: Remove MSMC port definitions

The MSMC port defines were added to help in the case when some ports
are not connected and have no cores attached. We can get the same
functionality by defined the number of cores on that port to zero.
This simplifies several code paths, do this here.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Change-Id: I3247fe37af7b86c3227e647b4f617fab70c8ee8a