[POWERPC] spufs: wrap mfc sdr access

SPRN_SDR1 and the SPE's MFC SDR are hypervisor resources and
are not accessible from a logical partition.  This change adds an
access wrapper.

When running on bare H/W, the spufs needs to only set the SPE's MFC SDR
to the value of the PPE's SPRN_SDR1 once at SPE initialization, so this
change renames mfc_sdr_set() to mfc_sdr_setup() and moves the
access of SPRN_SDR1 into the mmio wrapper.  It also removes the now
unneeded member mfc_sdr_RW from struct spu_priv1_collapsed.

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

--
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
index d0fb959..d41ad1d 100644
--- a/arch/powerpc/platforms/cell/spu_base.c
+++ b/arch/powerpc/platforms/cell/spu_base.c
@@ -805,7 +805,7 @@
 	if (ret)
 		goto out_unmap;
 	spin_lock_init(&spu->register_lock);
-	spu_mfc_sdr_set(spu, mfspr(SPRN_SDR1));
+	spu_mfc_sdr_setup(spu);
 	spu_mfc_sr1_set(spu, 0x33);
 	mutex_lock(&spu_mutex);