acpi: property: Let args be NULL in __acpi_node_get_property_reference

stable inclusion
from stable-v4.19.306
commit d60ab2f871564fa4cfe721e321002d490e885cdc
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I970CO


CVE: NA

--------------------------------

[ Upstream commit bef52aa0f3de1b7d8c258c13b16e577361dabf3a ]

fwnode_get_property_reference_args() may not be called with args argument
NULL on ACPI, OF already supports this. Add the missing NULL checks and
document this.

The purpose is to be able to count the references.

Fixes: 977d5ad3 ("ACPI: Convert ACPI reference args to generic fwnode reference args")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231109101010.1329587-2-sakari.ailus@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>