ARM: imx: clk-vf610: Add USBPHY clocks

This commit adds PLL7 which is required for USBPHY1. It also adds
the USB PHY and USB Controller clocks and the gates to enable them.

Acked-by: Jingchang Lu <jingchang.lu@freescale.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>