x86: make e820.c to have common functions

remove the duplicated copy of these functions.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index b54c79c..5faeab6 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -875,7 +875,7 @@
 		get_smp_config();
 #endif
 
-	e820_register_memory();
+	e820_setup_gap();
 	e820_mark_nosave_regions();
 
 #ifdef CONFIG_VT