target/ppc: Fix VRMA page size for ISA v3.0

target/ppc: Fix VRMA page size for ISA v3.0

Until v2.07s, the VRMA page size (L||LP) was encoded in LPCR[VRMASD].
In v3.0 that moved to the partition table PS field.

The powernv machine can now run KVM HPT guests on POWER9/10 CPUs with
this fix and the patch to add ASDR.

Fixes: 3367c62f522b ("target/ppc: Support for POWER9 native hash")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-ID: <20230730111842.39292-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
(cherry picked from commit 0e2a3ec36885f6d79a96230f582d4455878c6373)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>