pnv/xive2: Configure Virtualization Structure Tables through the PC

pnv/xive2: Configure Virtualization Structure Tables through the PC

Both the virtualization layer (VC) and presentation layer (PC) need to
be configured to access the VSTs. Since the information is redundant,
the xive model combines both into one set of tables and only the
definitions going through the VC are kept. The definitions through the
PC are ignored. That works well as long as firmware calls the VC for
all the tables.

For the NVG and NVC tables, it can make sense to only configure them
with the PC, since they are only used by the presenter. So this patch
allows firmware to configure the VST tables through the PC as well.
The definitions are still shared, since the VST tables can be set
through both the VC and/or PC, they are dynamically re-mapped in
memory by first deleting the memory subregion.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Kowal <kowal@linux.vnet.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>