MAINTAINERS: Update ps3vram block driver

Add myself as co-maintainer of the ps3vram block driver, and add linuxppc-dev
as a relevant mailing list.

I have been acting as maintainer of this driver for the last several years, and
if there is some inquiry regarding it I would like to be notified.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Jim Paris <jim@jtan.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

MAINTAINERS

@@ -7852,6 +7852,8 @@ F:	sound/ppc/snd_ps3*
 
 PS3VRAM DRIVER
 M:	Jim Paris <jim@jtan.com>
+M:	Geoff Levand <geoff@infradead.org>
+L:	linuxppc-dev@lists.ozlabs.org
 L:	cbe-oss-dev@lists.ozlabs.org
 S:	Maintained
 F:	drivers/block/ps3vram.c