x86: dts: Define a default TSC timer frequency

If for some reason, TSC timer frequency cannot be determined from
hardware, nor is it specified in the device tree, U-Boot will panic
resulting in endless reset during boot.

Let's define a default TSC timer frequency using the Kconfig value
CONFIG_X86_TSC_TIMER_FREQ (note: #include must be used instead of
/include/ otherwise the macro is not pre-processed).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/dts/galileo.dts b/arch/x86/dts/galileo.dts
index b5ba118..4120e8f 100644
--- a/arch/x86/dts/galileo.dts
+++ b/arch/x86/dts/galileo.dts
@@ -11,7 +11,8 @@
 /include/ "skeleton.dtsi"
 /include/ "reset.dtsi"
 /include/ "rtc.dtsi"
-/include/ "tsc_timer.dtsi"
+
+#include "tsc_timer.dtsi"
 
 / {
 	model = "Intel Galileo";
@@ -41,10 +42,6 @@
 		};
 	};
 
-	tsc-timer {
-		clock-frequency = <CONFIG_X86_TSC_TIMER_FREQ>;
-	};
-
 	mrc {
 		compatible = "intel,quark-mrc";
 		flags = <MRC_FLAG_SCRAMBLE_EN>;