clk: clk-uclass: Assign clk->dev before call .of_xlate

In order to make clk->dev available in ops->of_xlate() to get the
clock ID from the 'reg' property of the clock node, assign the
clk->dev before calling ops->of_xlate().

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>