ASoC: rsnd: adg: use __clk_get_name() instead of local clk_name[]

Current rsnd_adg_clk_dbg_info() is using locak clk_name[] to ndicating
clk name, but we don't want to use local clk_name[] everywhere when we
support R-Car Gen4 sound to handling non compatible clk naming.

This patch uses __clk_get_name() instead of local clk_name[] for it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87v8mz8wcs.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>