x86: Support relocation of FDT on start-up

With CONFIG_OF_CONTROL we may have an FDT in the BSS region. Relocate
it up with the rest of U-Boot to keep the rest of memory free.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/init_helpers.h b/arch/x86/include/asm/init_helpers.h
index 2f437e0..d018b29 100644
--- a/arch/x86/include/asm/init_helpers.h
+++ b/arch/x86/include/asm/init_helpers.h
@@ -38,5 +38,7 @@
 int status_led_set_r(void);
 int set_load_addr_r(void);
 int init_func_spi(void);
+int find_fdt(void);
+int prepare_fdt(void);
 
 #endif	/* !_INIT_HELPERS_H_ */