drivers/edac: fix pasemi kconfig depends

Fixed 'depends on PPC_PASEMI' in EDAC Kconfig.  Module PASEMI depends ONLY on
the PASEMI on PPC.

Was previously enabled for ALL PPC

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Egor N. Martovetsky <egor@pasemi.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>