[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/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index f4df04f..e1bd46a 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -16,9 +16,9 @@
 #include <linux/init.h>
 #include <linux/serial_8250.h>
 #include <linux/serial_reg.h>
+#include <linux/clk.h>
 
 #include <asm/io.h>
-#include <asm/hardware/clock.h>
 
 #include <asm/arch/common.h>
 #include <asm/arch/board.h>