ti: k3: Introduce lite device board support

ti: k3: Introduce lite device board support

Add device support for the 'lite' K3 devices. These will use modified
device addresses and allow for fewer cores to save memory.

Note: This family of devices are characterized by a single cluster
of ARMv8 processor upto a max of 4 processors and lack of a level 3
cache.

The first generation of this family is introduced with AM642.

See AM64X Technical Reference Manual (SPRUIM2, Nov 2020)
for further details: https://www.ti.com/lit/pdf/spruim2

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Change-Id: I8cd2c1c9a9434646d0c72fca3162dd5bc9bd692a