uboot-imx

x86: coreboot: Add default TSC frequency in the device tree

It was observed sometimes U-Boot as the coreboot payload fails to
boot on QEMU. This is because TSC calibration fails with no valid
frequency. This adds default TSC frequency in the device tree.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>