video: ep93xx: Prepare clock before using it

Use clk_prepare_enable()/clk_disable_unprepare() in preparation for switch
to Common Clock Framework.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210726140001.24820-5-nikita.shubin@maquefel.me

drivers/video/fbdev/ep93xx-fb.c

@@ -548,7 +548,7 @@ static int ep93xxfb_probe(struct platform_device *pdev)
 	}
 
 	ep93xxfb_set_par(info);
-	clk_enable(fbi->clk);
+	clk_prepare_enable(fbi->clk);
 
 	err = register_framebuffer(info);
 	if (err)
@@ -577,7 +577,7 @@ static int ep93xxfb_remove(struct platform_device *pdev)
 	struct ep93xx_fbi *fbi = info->par;
 
 	unregister_framebuffer(info);
-	clk_disable(fbi->clk);
+	clk_disable_unprepare(fbi->clk);
 	ep93xxfb_dealloc_videomem(info);
 	fb_dealloc_cmap(&info->cmap);