usb: chipidea: add flag for imx hsic implementation

NXP (Freecale) imx HSIC design has some special requirements, add
some flags at host code to handle them.

Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Peter Chen <peter.chen@nxp.com>