usb: ehci-sh: Add PHY init function with platform data

In devices using ehci-sh, initialization of the PHY may be necessary.
This adds platform data to ehci-sh and provide function to initialize PHY.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
CC: Shimoda, Yoshihiro <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>