x86: Remove unnecessary find_fdt(), prepare_fdt() functions

These are no-longer needed so drop them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/include/asm/init_helpers.h

@@ -13,7 +13,5 @@ int calculate_relocation_address(void);
 int init_cache_f_r(void);
 int init_bd_struct_r(void);
 int init_func_spi(void);
-int find_fdt(void);
-int prepare_fdt(void);
 
 #endif	/* !_INIT_HELPERS_H_ */