[ARM] Move asm/hardware/clock.h to linux/clk.h

This is needs to be visible to other architectures using the AMBA
bus and peripherals.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/arch-omap/system.h b/include/asm-arm/arch-omap/system.h
index 9af415d..6724a81 100644
--- a/include/asm-arm/arch-omap/system.h
+++ b/include/asm-arm/arch-omap/system.h
@@ -5,8 +5,9 @@
 #ifndef __ASM_ARCH_SYSTEM_H
 #define __ASM_ARCH_SYSTEM_H
 #include <linux/config.h>
+#include <linux/clk.h>
+
 #include <asm/mach-types.h>
-#include <asm/hardware/clock.h>
 #include <asm/hardware.h>
 #include <asm/arch/prcm.h>