Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>