blackfin: Use generic clkdev.h header

The generic header file is equivalent to the blackfin version, so
just use the generic one.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

arch/blackfin/include/asm/Kbuild

 generic-y += bugs.h
+generic-y += clkdev.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h

arch/blackfin/include/asm/clkdev.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ASM_CLKDEV__H_
-#define __ASM_CLKDEV__H_
-
-#include <linux/slab.h>
-
-static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)
-{
-	return kzalloc(size, GFP_KERNEL);
-}
-
-#ifndef CONFIG_COMMON_CLK
-#define __clk_put(clk)
-#define __clk_get(clk) ({ 1; })
-#endif
-
-#endif