power: supply: core: Use device_property_string_array_count()

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2071846
Tested: This is one of a series of patch sets to enable Arm SystemReady IR
 support in the kernel for NXP i.MX8 platforms.  This set updates the
 power subsystem.  This set has been tested via simple boot tests and
 the CI loop.

commit 1c97db1
Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date:   Wed Feb 2 20:23:25 2022 +0200

    power: supply: core: Use device_property_string_array_count()

    Use device_property_string_array_count() to get number of strings
    in a string array property.

    Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
    Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
    (cherry picked from commit 1c97db1)

Signed-off-by: Al Stone <ahs3@redhat.com>

Author: Al Stone

drivers/power/supply/power_supply_core.c

@@ -283,8 +283,7 @@ static int power_supply_check_supplies(struct power_supply *psy)
 	if (!psy->dev.parent)
 		return 0;
 
-	nval = device_property_read_string_array(psy->dev.parent,
-						 "supplied-from", NULL, 0);
+	nval = device_property_string_array_count(psy->dev.parent, "supplied-from");
 	if (nval <= 0)
 		return 0;