x86, mm: Move init_memory_mapping calling out of setup.c

Now init_memory_mapping is called two times, later will be called for every
ram ranges.

Could put all related init_mem calling together and out of setup.c.

Actually, it reverts commit 1bbbbe7
    x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping.
will address that later with complete solution include handling hole under 4g.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-5-git-send-email-yinghai@kernel.org
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 98ac76d..dd1a888 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -602,7 +602,7 @@
 #ifndef __ASSEMBLY__
 
 extern int direct_gbpages;
-void probe_page_size_mask(void);
+void init_mem_mapping(void);
 
 /* local pte updates need not use xchg for locking */
 static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)