USB: host: ohci-at91: Move global variables to private struct

This patch move AT91 OHCI global variables (clocks ptr and clocked
boolean) to private struct ohci_at91_priv, stored in ohci->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>