sh: Introduce clk_always_enable() function

Add SuperH specific funcion clk_always_enable(), useful to enable MSTPCR
bits in processor or board specific code.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

include/asm-sh/clock.h

@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/seq_file.h>
 #include <linux/clk.h>
+#include <linux/err.h>
 
 struct clk;
 
@@ -47,6 +48,22 @@ void clk_recalc_rate(struct clk *);
 int clk_register(struct clk *);
 void clk_unregister(struct clk *);
 
+static inline int clk_always_enable(const char *id)
+{
+	struct clk *clk;
+	int ret;
+
+	clk = clk_get(NULL, id);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	ret = clk_enable(clk);
+	if (ret)
+		clk_put(clk);
+
+	return ret;
+}
+
 /* the exported API, in addition to clk_set_rate */
 /**
  * clk_set_rate_ex - set the clock rate for a clock source, with additional parameter