supports host only mode and the code is ported from
host/xhci-mtk.c
IPPC register shared between host and device is moved
into common glue layer.
Signed-off-by: NChunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>