Move all declarations of free_initmem() to linux/mm.h

Move all declarations of free_initmem() to linux/mm.h so that there's only one
and it's used by everything.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-c6x-dev@linux-c6x.org
cc: microblaze-uclinux@itee.uq.edu.au
cc: linux-sh@vger.kernel.org
cc: sparclinux@vger.kernel.org
cc: x86@kernel.org
cc: linux-mm@kvack.org

init/main.c

@@ -87,7 +87,6 @@ extern void mca_init(void);
 extern void sbus_init(void);
 extern void prio_tree_init(void);
 extern void radix_tree_init(void);
-extern void free_initmem(void);
 #ifndef CONFIG_DEBUG_RODATA
 static inline void mark_rodata_ro(void) { }
 #endif