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/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index 986afbc..a36c43a 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -226,7 +226,8 @@
 static void context_check_map(void) { }
 #endif
 
-void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
+void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
+			struct task_struct *tsk)
 {
 	unsigned int i, id, cpu = smp_processor_id();
 	unsigned long *map;