[ARM] OMAP: clockdomain: add clkdm_get_pwrdm()

Add clkdm_get_pwrdm() to the clockdomain code.  It will return a
pointer to the powerdomain struct that the clockdomain is contained
within.  Used by the PM code.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-omap2/clockdomain.c

@@ -315,6 +315,22 @@ int clkdm_for_each(int (*fn)(struct clockdomain *clkdm))
 }
 
 
+/**
+ * clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
+ * @clkdm: struct clockdomain *
+ *
+ * Return a pointer to the struct powerdomain that the specified clockdomain
+ * 'clkdm' exists in, or returns NULL if clkdm argument is NULL.
+ */
+struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
+{
+	if (!clkdm)
+		return NULL;
+
+	return clkdm->pwrdm;
+}
+
+
 /* Hardware clockdomain control */
 
 /**