x86: remove duplicated e820 func in setup.h

we already have them in e820.h
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/asm-x86/setup.h

@@ -50,15 +50,9 @@ extern struct boot_params boot_params;
  */
 #define LOWMEMSIZE()	(0x9f000)
 
-struct e820entry;
-
 char * __init machine_specific_memory_setup(void);
 char *memory_setup(void);
 
-int __init copy_e820_map(struct e820entry *biosmap, int nr_map);
-void __init add_memory_region(unsigned long long start,
-			      unsigned long long size, int type);
-
 
 void __init i386_start_kernel(void);