ARM i.MX: prepare for common clock framework

- Add necessary #ifdefs for CONFIG_COMMON_CLOCK
- Add a global spinlock to protect the CCM registers

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/plat-mxc/clock.c b/arch/arm/plat-mxc/clock.c
index 2ed3ab1..5079787 100644
--- a/arch/arm/plat-mxc/clock.c
+++ b/arch/arm/plat-mxc/clock.c
@@ -41,6 +41,7 @@
 #include <mach/clock.h>
 #include <mach/hardware.h>
 
+#ifndef CONFIG_COMMON_CLK
 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);
 
@@ -200,6 +201,16 @@
 }
 EXPORT_SYMBOL(clk_get_parent);
 
+#else
+
+/*
+ * Lock to protect the clock module (ccm) registers. Used
+ * on all i.MXs
+ */
+DEFINE_SPINLOCK(imx_ccm_lock);
+
+#endif /* CONFIG_COMMON_CLK */
+
 /*
  * Get the resulting clock rate from a PLL register value and the input
  * frequency. PLLs with this register layout can at least be found on