ppc/pnv: Set P10 core xscom region size to match hardware

ppc/pnv: Set P10 core xscom region size to match hardware

The P10 core xscom memory regions overlap because the size is wrong.
The P10 core+L2 xscom region size is allocated as 0x1000 (with some
unused ranges). "EC" is used as a closer match, as "EX" includes L3
which has a disjoint xscom range that would require a different
region if it were implemented.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Message-ID: <20230706053923.115003-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>