Revert "usb: chipidea: imx: enable CI_HDRC_SET_NON_ZERO_TTHA"

This reverts commit e765bfb7.

In the most of cases, we only use one transaction per frame and the
frame rate may be high, If the platforms want to support multiple
transactions but less frame rate cases like [1] and [2], it can set
"non-zero-ttctrl-ttha" at dts.

[1] http://www.spinics.net/lists/linux-usb/msg123125.html
[2] http://www.spinics.net/lists/linux-usb/msg118679.html



Signed-off-by: Peter Chen <peter.chen@nxp.com>