sandbox: Update dts files to reduce SPL size

At present there are require a few devices in the devicetree which are
not actually used in SPL. This will cause problems with the new
of-platdata, since it will try to instantiate devices which are not
compiled into U-Boot.

Update the devicetree to remove these devices from SPL.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/dts/sandbox.dts b/arch/sandbox/dts/sandbox.dts
index 8b50a40..a8938a3 100644
--- a/arch/sandbox/dts/sandbox.dts
+++ b/arch/sandbox/dts/sandbox.dts
@@ -41,7 +41,7 @@
 
 	cros_ec: cros-ec {
 		reg = <0 0>;
-		u-boot,dm-pre-reloc;
+		u-boot,dm-pre-proper;
 		compatible = "google,cros-ec-sandbox";
 	};
 
@@ -83,7 +83,7 @@
 	};
 
 	spi: spi@0 {
-		u-boot,dm-pre-reloc;
+		u-boot,dm-pre-proper;
 		#address-cells = <1>;
 		#size-cells = <0>;
 		reg = <0 0>;