[POWERPC] ps3: add lpar addressing

Adds some needed bits for a config option PS3_USE_LPAR_ADDR that disables
the PS3 lpar address translation mechanism.  This is a currently needed
workaround for limitations in the design of the generic cell spu support.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>