clk: sunxi-ng: switch to of_clk_hw_register() for registering clks

Commit 89a5ddcc ("clk: Add of_clk_hw_register() API for early clk
drivers") introduces a new API for registering clks, which allows the
user to directly specify a device node, even if there is no struct
device attached to it. The device node is used for local DT clock-names
matching.

Switch to of_clk_hw_register() so that local DT clock-names matching
works.

Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>