powerpc/mm: Abstraction for switch_mmu_context()

How we switch MMU context differs between hash and radix. For hash we
need to switch the SLB details and for radix we need to switch the PID
SPR.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/kernel/swsusp.c b/arch/powerpc/kernel/swsusp.c
index 6669b17..6ae9bd5 100644
--- a/arch/powerpc/kernel/swsusp.c
+++ b/arch/powerpc/kernel/swsusp.c
@@ -31,6 +31,6 @@
 void restore_processor_state(void)
 {
 #ifdef CONFIG_PPC32
-	switch_mmu_context(current->active_mm, current->active_mm);
+	switch_mmu_context(current->active_mm, current->active_mm, NULL);
 #endif
 }