x86: Update device tree for Chromium OS verified boot

The standard image generated by U-Boot on x86 is u-boot.rom. Add a
separate image called image.bin for verified boot. This supports
verification in TPL of which SPL/U-Boot to start, then jumping to the
correct one, with SPL setting up the SDRAM and U-Boot proper providing
the user interface if needed.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>

arch/x86/dts/u-boot.dtsi

@@ -6,9 +6,23 @@
 
 #include <config.h>
 
-#ifdef CONFIG_ROM_SIZE
+#ifdef CONFIG_CHROMEOS
 / {
 	binman {
+		multiple-images;
+		rom: rom {
+		};
+	};
+};
+#else
+/ {
+	rom: binman {
+	};
+};
+#endif
+
+#ifdef CONFIG_ROM_SIZE
+&rom {
 		filename = "u-boot.rom";
 		end-at-4gb;
 		sort-by-offset;
@@ -116,6 +130,5 @@
 			offset = <CONFIG_SYS_X86_START16>;
 		};
 #endif
-	};
 };
 #endif