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/configs/qemu-x86_defconfig b/configs/qemu-x86_defconfig
index ebdb892..8c86931 100644
--- a/configs/qemu-x86_defconfig
+++ b/configs/qemu-x86_defconfig
@@ -23,6 +23,7 @@
 CONFIG_DM_PCI=y
 CONFIG_DM_RTC=y
 CONFIG_SYS_NS16550=y
+CONFIG_TIMER=y
 CONFIG_USB=y
 CONFIG_DM_USB=y
 CONFIG_VIDEO_VESA=y