target-ppc: Remove POWER5+ v0.0 that never existed

target-ppc: Remove POWER5+ v0.0 that never existed

IBM uses low 16bits to specify the chip version of a POWER CPU.
So there has never been an actual silicon with PVR = 0x003B0000.
The first silicon would have PVR 0x003B0100 but it is very unlikely
to find it in any machine shipped to any customer as it was too raw.

This removes CPU_POWERPC_POWER5P_v00 definition and changes
POWER5+ and POWERgs aliases (which are synonyms) to point to
POWER5+_v2.1 which can still be found in real machines.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Andreas Färber <afaerber@suse.de>
[agraf: fix commit message]
Signed-off-by: Alexander Graf <agraf@suse.de>