microblaze: Replace <linux/clk-provider.h> by <linux/of_clk.h>

The MicroBlaze platform code is not a clock provider, and just needs to
call of_clk_init().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20201110154851.3285695-1-geert+renesas@glider.be


Signed-off-by: Michal Simek <michal.simek@xilinx.com>