[POWERPC] PS3: Kill unused ps3_repository_bump_device()

PS3: Kill unused routine ps3_repository_bump_device().

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>