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

drivers/usb/chipidea/ci_hdrc_imx.c

@@ -250,7 +250,6 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
 	struct ci_hdrc_platform_data pdata = {
 		.name		= dev_name(&pdev->dev),
 		.capoffset	= DEF_CAPOFFSET,
-		.flags		= CI_HDRC_SET_NON_ZERO_TTHA,
 	};
 	int ret;
 	const struct of_device_id *of_id;