x86: mm/init_XX.c declare functions before they get used

included <asm/smp.h> in mm/init_32.c for zap_low_mappings()

declared free_initmem() in asm-x86/page_XX.h

Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
diff --git a/include/asm-x86/page_32.h b/include/asm-x86/page_32.h
index ab85287..c9dd069 100644
--- a/include/asm-x86/page_32.h
+++ b/include/asm-x86/page_32.h
@@ -96,6 +96,7 @@
 extern unsigned long init_memory_mapping(unsigned long start,
 					 unsigned long end);
 extern void initmem_init(unsigned long, unsigned long);
+extern void free_initmem(void);
 extern void setup_bootmem_allocator(void);