USB: host: ehci-atmel: Move global variables to private struct

This patch move Atmel EHCI global variables (clocks ptr and clocked
boolean) to private struct atmel_ehci_priv, stored in ehci->priv.

Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>