sh: of-generic: Add missing #include <asm/clock.h>

arch/sh/boards/of-generic.c:146:20: warning: no previous prototype for 'arch_init_clk_ops' [-Wmissing-prototypes]

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: John Paul Adrian Glaubitz <[e-mail]>
Link: https://lore.kernel.org/r/94262[e-mail]
Signed-off-by: John Paul Adrian Glaubitz <[e-mail]>

arch/sh/boards/of-generic.c

···
 #include <linux/of_fdt.h>
 #include <linux/clocksource.h>
 #include <linux/irqchip.h>
+
+#include <asm/clock.h>
 #include <asm/machvec.h>
 #include <asm/rtc.h>