clk: sunxi: Don't call clk_hw_get_name() on a hw that isn't registered

The implementation of clk_hw_get_name() relies on the clk_core
associated with the clk_hw pointer existing. If of_clk_hw_register()
fails, there isn't a clk_core created yet, so calling clk_hw_get_name()
here fails. Extract the name first so we can print it later.

Fixes: 1d80c142 ("clk: sunxi-ng: Add common infrastructure")
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>