Moves dealing with VSoC layout to vsoc_lib library

After moving the logic to calculate region sizes to vsoc_lib the
knowledge about shared memory layout was split between two independent
modules. It makes sense to let the vsoc_lib library be in charge of
the details of the memory layout while keeping the ivsering just
knowing how to 'serve'.

The information about the memory layout that the ivserver and other
host processes need is accessible through a simple interface defined
in common/vsoc/lib/vsoc_memory.h.

Bug: 79602833
Test: run locally
Change-Id: Ib80bb42bd0d3cdb1dea635b2153258d31d7c92a7