clk: at91: fix clk_programmable_set_parent()

Since commit 1bdf023 ("clk: at91: make use of syscon/regmap
internally"), clk_programmable_set_parent() is always selecting the
first parent (AKA slow_clk), no matter what's passed in the 'index'
parameter.

Fix that by initializing the pckr variable to the index value.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reported-by: Hans Verkuil <hans.verkuil@cisco.com>
Fixes: 1bdf023 ("clk: at91: make use of syscon/regmap internally")
Cc: <stable@vger.kernel.org>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/1468828152-18389-1-git-send-email-boris.brezillon@free-electrons.com

drivers/clk/at91/clk-programmable.c

@@ -99,7 +99,7 @@ static int clk_programmable_set_parent(struct clk_hw *hw, u8 index)
 	struct clk_programmable *prog = to_clk_programmable(hw);
 	const struct clk_programmable_layout *layout = prog->layout;
 	unsigned int mask = layout->css_mask;
-	unsigned int pckr = 0;
+	unsigned int pckr = index;
 
 	if (layout->have_slck_mck)
 		mask |= AT91_PMC_CSSMCK_MCK;