clkdev: Export clk_register_clkdev

So it can be used from modules such as clk-test.ko.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

diff --cc drivers/clk/clkdev.c
Simple merge