Choose rpa_vscsi.c over iseries_vscsi.c when building both pseries and
iseries.  This fixes a link error.
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>