clk: bcm: rpi: Switch to clk_hw_register_clkdev

clk: bcm: rpi: Switch to clk_hw_register_clkdev

Since we don't care about retrieving the clk_lookup structure pointer
returned by clkdev_hw_create, we can just use the clk_hw_register_clkdev
function.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/59f6208b6fe3367e735b0cca4f65c2c937639af9.1592210452.git-series.maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>