powerpc/32: Add missing prototypes for (early|machine)_init()

early_init() and machine_init() have no prototype, add one in
asm-prototypes.h.

Fixes the following warnings (treated as error in W=1):
  arch/powerpc/kernel/setup_32.c:68:30: error: no previous prototype for ‘early_init’
  arch/powerpc/kernel/setup_32.c:99:21: error: no previous prototype for ‘machine_init’

Signed-off-by: Mathieu Malaterre <malat@debian.org>
[mpe: Move them to asm-prototypes.h, drop other functions]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/asm-prototypes.h

@@ -95,7 +95,10 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
 			 struct pt_regs *regs);
 int
 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct timeval __user *tvp);
+unsigned long __init early_init(unsigned long dt_ptr);
+void __init machine_init(u64 dt_ptr);
 #endif
+
 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
 		      u32 len_high, u32 len_low);
 long sys_switch_endian(void);

arch/powerpc/kernel/setup_32.c

@@ -39,6 +39,7 @@
 #include <asm/udbg.h>
 #include <asm/code-patching.h>
 #include <asm/cpu_has_feature.h>
+#include <asm/asm-prototypes.h>
 
 #define DBG(fmt...)