at91/avr32/atmel_lcdfb: prepare clk before calling enable

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: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/atmel_lcdfb.c

@@ -902,14 +902,14 @@ static int __init atmel_lcdfb_init_fbinfo(struct atmel_lcdfb_info *sinfo)
 
 static void atmel_lcdfb_start_clock(struct atmel_lcdfb_info *sinfo)
 {
-	clk_enable(sinfo->bus_clk);
-	clk_enable(sinfo->lcdc_clk);
+	clk_prepare_enable(sinfo->bus_clk);
+	clk_prepare_enable(sinfo->lcdc_clk);
 }
 
 static void atmel_lcdfb_stop_clock(struct atmel_lcdfb_info *sinfo)
 {
-	clk_disable(sinfo->bus_clk);
-	clk_disable(sinfo->lcdc_clk);
+	clk_disable_unprepare(sinfo->bus_clk);
+	clk_disable_unprepare(sinfo->lcdc_clk);
 }