usb: musb: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Instead of a per-device static timer variable, a spare timer "dev_timer"
is added to the musb structure for devices to use for their per-device
timer.

Cc: linux-usb@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>