clk: bcm: rpi: Create helper to retrieve private data

The RaspberryPi firmware clocks driver uses in several instances a
container_of to retrieve the struct raspberrypi_clk_data from a pointer
to struct clk_hw. Let's create a small function to avoid duplicating it
all over the place.

Acked-by: Stephen Boyd <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>
Signed-off-by: Dave Stevenson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Florian Fainelli <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/bcm/clk-raspberrypi.c

···
 	struct raspberrypi_clk *rpi;
 };
 
+static inline
+const struct raspberrypi_clk_data *clk_hw_to_data(const struct clk_hw *hw)
+{
+	return container_of(hw, struct raspberrypi_clk_data, hw);
+}
+
 struct raspberrypi_clk_variant {
 	bool		export;
 	char		*clkdev;
···
 
 static int raspberrypi_fw_is_prepared(struct clk_hw *hw)
 {
-	struct raspberrypi_clk_data *data =
-		container_of(hw, struct raspberrypi_clk_data, hw);
+	const struct raspberrypi_clk_data *data = clk_hw_to_data(hw);
 	struct raspberrypi_clk *rpi = data->rpi;
 	u32 val = 0;
 	int ret;
···
 static unsigned long raspberrypi_fw_get_rate(struct clk_hw *hw,
 					     unsigned long parent_rate)
 {
-	struct raspberrypi_clk_data *data =
-		container_of(hw, struct raspberrypi_clk_data, hw);
+	const struct raspberrypi_clk_data *data = clk_hw_to_data(hw);
 	struct raspberrypi_clk *rpi = data->rpi;
 	u32 val = 0;
 	int ret;
···
 static int raspberrypi_fw_set_rate(struct clk_hw *hw, unsigned long rate,
 				   unsigned long parent_rate)
 {
-	struct raspberrypi_clk_data *data =
-		container_of(hw, struct raspberrypi_clk_data, hw);
+	const struct raspberrypi_clk_data *data = clk_hw_to_data(hw);
 	struct raspberrypi_clk *rpi = data->rpi;
 	u32 _rate = rate;
 	int ret;
···
 static int raspberrypi_fw_dumb_determine_rate(struct clk_hw *hw,
 					      struct clk_rate_request *req)
 {
-	struct raspberrypi_clk_data *data =
-		container_of(hw, struct raspberrypi_clk_data, hw);
+	const struct raspberrypi_clk_data *data = clk_hw_to_data(hw);
 	struct raspberrypi_clk_variant *variant = data->variant;
 
 	/*