x86: Convert to use driver model timer

Convert all x86 boards to use driver model tsc timer.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/dts/efi.dts b/arch/x86/dts/efi.dts
index 1f50428..6cd8116 100644
--- a/arch/x86/dts/efi.dts
+++ b/arch/x86/dts/efi.dts
@@ -7,6 +7,7 @@
 /dts-v1/;
 
 /include/ "skeleton.dtsi"
+/include/ "tsc_timer.dtsi"
 
 / {
 	model = "EFI";
@@ -16,6 +17,10 @@
 		stdout-path = &serial;
 	};
 
+	tsc-timer {
+		clock-frequency = <1000000000>;
+	};
+
 	serial: serial {
 		compatible = "efi,uart";
 	};