ALSA: hda: cs35l41: Fix NULL pointer dereference in cs35l41_hda_read_acpi()

ALSA: hda: cs35l41: Fix NULL pointer dereference in cs35l41_hda_read_acpi()

The acpi_get_first_physical_node() function can return NULL, in which
case the get_device() function also returns NULL, but this value is
then dereferenced without checking,so add a check to prevent a crash.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 7b2f3eb492da ("ALSA: hda: cs35l41: Add support for CS35L41 in HDA systems")
Cc: stable@vger.kernel.org
Signed-off-by: Denis Arefev <arefev@swemel.ru>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251202101338.11437-1-arefev@swemel.ru