[RESEND PATCH v6, 3/5] usb: xhci-mtk: make IPPC register optional

[Chunfeng Yun]

On Wed, 2016-09-21 at 13:54 +0800, Chunfeng Yun wrote:
> Make IPPC register optional to support host side of dual-role mode,
> due to it is moved into common glue layer for simplification.
> 
> Signed-off-by: Chunfeng Yun <chunfeng.yun at mediatek.com>
> ---
>  drivers/usb/host/xhci-mtk.c |   36 +++++++++++++++++++++++++++++-------
>  1 file changed, 29 insertions(+), 7 deletions(-)

Hi Mathias,

    Would you please take a little time out of your busy schedule and
help review this patch?

    Thank you very much.