component has io_mutex, but it had been used at
snd_soc_component_update_bits_legacy() only which does read and write.

	static int snd_soc_component_update_bits_legacy(...)
	{
		...
=>		mutex_lock(&component->io_mutex);
		...
		old = snd_soc_component_read(...);
		...
		ret = snd_soc_component_write(...);
		...
=>		mutex_unlock(&component->io_mutex);
		...
	}

It is pointless if it is not used with both read and write functions.
This patch uses io_mutex correctly with read/write.
Here, xxx_no_lock() is local functions.

	static int snd_soc_component_read(...)
	{
		...
=>		mutex_lock(&component->io_mutex);
		val = soc_component_read_no_lock(...);
=>		mutex_unlock(&component->io_mutex);
		...
	}

	static int snd_soc_component_write(...)
	{
		...
=>		mutex_lock(&component->io_mutex);
		ret = soc_component_write_no_lock(...);
=>		mutex_unlock(&component->io_mutex);
		...
	}

	static int snd_soc_component_update_bits_legacy(...)
	{
		...
=>		mutex_lock(&component->io_mutex);
		...
		old = soc_component_read_no_lock(...);
		...
		ret = soc_component_write_no_lock(...);
		...
=>		mutex_unlock(&component->io_mutex);
		...
	}
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87r1uf4mfa.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>