Use the the tcb counter width to compute the maximum time that can be
represented using the slow clock source instead of the static 16 bit width.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>