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/efi-x86_payload.dts b/arch/x86/dts/efi-x86_payload.dts
index 5ccb986..087865f 100644
--- a/arch/x86/dts/efi-x86_payload.dts
+++ b/arch/x86/dts/efi-x86_payload.dts
@@ -12,7 +12,8 @@
 /include/ "keyboard.dtsi"
 /include/ "reset.dtsi"
 /include/ "rtc.dtsi"
-/include/ "tsc_timer.dtsi"
+
+#include "tsc_timer.dtsi"
 
 / {
 	model = "EFI x86 Payload";
@@ -30,10 +31,6 @@
 		stdout-path = "/serial";
 	};
 
-	tsc-timer {
-		clock-frequency = <1000000000>;
-	};
-
 	pci {
 		compatible = "pci-x86";
 		u-boot,dm-pre-reloc;