sh: modify clock-sh7757 for renesas_usbhs

The renesas_usbhs driver doesn't use the clk functions. So, even if we
adds "CLKDEV_DEV_ID("renesas_usbhs.0", ...)" only, we cannot use the USB
controller because clk_late_init() will disable the clock by "usb0".
So, the patch also removes the "CLKDEV_CON_ID("usb0", ...)".

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>