x86: chromebook_link64: Correct the image layout

At present the image layout is not correct, since it uses the SDRAM
address of the 64-bit U-Boot as the ROM address. Fix this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/chromebook_link64_defconfig b/configs/chromebook_link64_defconfig
index d65b5c6..4eadf5a 100644
--- a/configs/chromebook_link64_defconfig
+++ b/configs/chromebook_link64_defconfig
@@ -17,8 +17,10 @@
 CONFIG_HAVE_MRC=y
 CONFIG_SMP=y
 CONFIG_HAVE_VGA_BIOS=y
+CONFIG_X86_OFFSET_U_BOOT=0xffa00000
 CONFIG_FIT=y
 CONFIG_SPL_LOAD_FIT=y
+# CONFIG_USE_SPL_FIT_GENERATOR is not set
 CONFIG_BOOTSTAGE=y
 CONFIG_BOOTSTAGE_REPORT=y
 CONFIG_SHOW_BOOT_PROGRESS=y