ALSA: cs35l41: Fix for old systems which do not support command

Some older laptops using cs35l41 use firmware which does not support
the CSPL_MBOX_CMD_SPK_OUT_ENABLE command.
Firmware versions v0.28.0 and older do not support this command.

Fixes: fa3efcc3

 ("ALSA: cs35l41: Use mbox command to enable speaker output for external boost")
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20231117163609.823627-3-sbinding@opensource.cirrus.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>