video: fbdev: simplefb: Stop including <linux/clk-provider.h>

Simplefb is not a clock provider, but it uses of_clk_get_parent_count(),
so it can just include <linux/of_clk.h> instead.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>