powerpc: Merge 32-bit and 64-bit setup_arch()

There is little enough differences now.

mpe: Add a/p/k/setup.h to contain the prototypes and empty versions of
functions we need, rather than using weak functions. Add a few other
empty versions to avoid as many #ifdefs as possible in the code.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index fa3e3c4..9c23baa 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -351,7 +351,6 @@
 extern int rtas_set_indicator(int indicator, int index, int new_value);
 extern int rtas_set_indicator_fast(int indicator, int index, int new_value);
 extern void rtas_progress(char *s, unsigned short hex);
-extern void rtas_initialize(void);
 extern int rtas_suspend_cpu(struct rtas_suspend_me_data *data);
 extern int rtas_suspend_last_cpu(struct rtas_suspend_me_data *data);
 extern int rtas_online_cpus_mask(cpumask_var_t cpus);
@@ -460,9 +459,11 @@
 /* Not the best place to put pSeries_coalesce_init, will be fixed when we
  * move some of the rtas suspend-me stuff to pseries */
 extern void pSeries_coalesce_init(void);
+void rtas_initialize(void);
 #else
 static inline int page_is_rtas_user_buf(unsigned long pfn) { return 0;}
 static inline void pSeries_coalesce_init(void) { }
+static inline void rtas_initialize(void) { };
 #endif
 
 extern int call_rtas(const char *, int, int, unsigned long *, ...);