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/qemu-x86_q35.dts b/arch/x86/dts/qemu-x86_q35.dts
index df30c89..0b685c8 100644
--- a/arch/x86/dts/qemu-x86_q35.dts
+++ b/arch/x86/dts/qemu-x86_q35.dts
@@ -22,6 +22,7 @@
 /include/ "serial.dtsi"
 /include/ "keyboard.dtsi"
 /include/ "rtc.dtsi"
+/include/ "tsc_timer.dtsi"
 
 / {
 	model = "QEMU x86 (Q35)";
@@ -55,6 +56,10 @@
 		};
 	};
 
+	tsc-timer {
+		clock-frequency = <1000000000>;
+	};
+
 	pci {
 		compatible = "pci-x86";
 		#address-cells = <3>;