uboot-imx

usb: xhci-mem: Fix scratchpad array issue

After updating the value of dev_context_ptrs[0], we should flush this
from cache to memory. Otherwise the xhci controller won't use it.

Signed-off-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Marek Vasut <marex@denx.de>