powerpc/64s/hash: Provide arch_setup_exec() hooks for hash slice setup

This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/thread_info.h

@@ -72,6 +72,12 @@ static inline struct thread_info *current_thread_info(void)
 }
 
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void arch_setup_new_exec(void);
+#define arch_setup_new_exec arch_setup_new_exec
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 /*