x86: Don't include reset driver in SPL

We don't normally need this driver in TPL/SPL, so drop it for now. It can
be enabled by individual boards if needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/dts/reset.dtsi

 / {
 	reset: reset {
 		compatible = "x86,reset";
-		u-boot,dm-pre-reloc;
+		u-boot,dm-pre-proper;
 	};
 };