[POWERPC] Refresh ppc64_defconfig and enable pasemi-related options

Refresh ppc64_defconfig, add PPC_PASEMI and various options that the
common boards there need:

* Chip drivers (iommu, ethernet, IDE, CF, EDAC, MDIO/PHY)
* PCMCIA
* PATA_PCMCIA
* RTC_CLASS
* SATA_MV
* SATA_SIL24
* IP_PNP + NFS_ROOT for diskless booting

+ possibly some other things I might have missed to list
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>