ARM: Kirkwood: clk_register_gate_fn: add fn assignment

In commit:
    98d9986c ARM: Kirkwood: Replace clock gating
the kirkwood clock gating has been reworked. A custom variant of
clock gating, that calls a custom function before gating the clock
off, has been introduced. However in clk_register_gate_fn() this
custom function "fn" is never assigned.

This patch adds the missing fn assignment.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: NMarc Kleine-Budde <mkl@blackshift.org>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NOlof Johansson <olof@lixom.net>

arch/arm/mach-kirkwood/common.c

@@ -159,6 +159,7 @@ static struct clk __init *clk_register_gate_fn(struct device *dev,
 	gate_fn->gate.flags = clk_gate_flags;
 	gate_fn->gate.lock = lock;
 	gate_fn->gate.hw.init = &init;
+	gate_fn->fn = fn;
 
 	/* ops is the gate ops, but with our disable function */
 	if (clk_gate_fn_ops.disable != clk_gate_fn_disable) {