usb: renesas_usbhs: Add multiple clocks management

R-Car Gen3 needs to enable clocks of both host and peripheral.
Since [eo]hci-platform disables the reset(s) when the drivers are
removed, renesas_usbhs driver doesn't work correctly. To fix this
issue, this patch adds multiple clocks management on this
renesas_usbhs driver.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>