target-ppc: Add POWER7 SPRs

This adds TIR/SIAR/SDAR/MMCRA/MMCR0/MMCR1.

This redefines UMMCRA (was MCCRA) and defines hypv version of if.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
target-ppc: Refactor init_proc_POWER8

This duplicates code of init_proc_POWER7() in init_proc_POWER8() as
there will be registers implemented in POWER7 and missing in POWER8
so we need separate init functions for POWER7 and POWER8.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
target-ppc: Add POWER8 SPRs

This adds helper which adds TAR/BESCRS/BESCRSU/BESCRR/BESCRRU/
EBBHR/EBBRR/BESCR/TFHAR/TFIAR/TEXASR/TEXASRU SPRs.

This adds MMCR2/FSCR/MMCRS SPRs.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
target-ppc: Enable PPR and VRSAVE SPRs migration

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
KVM: target-ppc: Enable transactional state migration

This adds migration support for registers saved before transaction started.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
spapr: Enable DABRX special register

This advertises Data Address Breakpoint Register Extension (DABRX) to
the guest via hyperrtas list and enables it to migrate.

This implements H_SET_XDABR.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>