x86: itss: Tidy up bind() for of-platdata-inst

With the standard of-platdata we must fix up driver_data manually. With
of-platadata-inst this is not necessary, since it is added to the device
by dtoc.

Update the code to handle this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/cpu/intel_common/itss.c b/arch/x86/cpu/intel_common/itss.c
index 588a512..1eff030 100644
--- a/arch/x86/cpu/intel_common/itss.c
+++ b/arch/x86/cpu/intel_common/itss.c
@@ -153,8 +153,9 @@
 
 static int itss_bind(struct udevice *dev)
 {
-	/* This is not set with of-platdata, so set it manually */
-	if (CONFIG_IS_ENABLED(OF_PLATDATA))
+	/* This is not set with basic of-platdata, so set it manually */
+	if (CONFIG_IS_ENABLED(OF_PLATDATA) &&
+	    !CONFIG_IS_ENABLED(OF_PLATDATA_INST))
 		dev->driver_data = X86_IRQT_ITSS;
 
 	return 0;