sm8450-common: Use soong_config_set to set xiaomi powershare variable

Change-Id: Id00f757720800fbf4ee94bedee71edb6fedc5643

BoardConfigCommon.mk

@@ -192,9 +192,7 @@ BOARD_USES_QCOM_HARDWARE := true
 TARGET_BOARD_PLATFORM := taro
 
 # PowerShare
-SOONG_CONFIG_NAMESPACES += XIAOMI_POWERSHARE
-SOONG_CONFIG_XIAOMI_POWERSHARE := WIRELESS_TX_ENABLE_PATH
-SOONG_CONFIG_XIAOMI_POWERSHARE_WIRELESS_TX_ENABLE_PATH := /sys/class/qcom-battery/reverse_chg_mode
+$(call soong_config_set, XIAOMI_POWERSHARE, WIRELESS_TX_ENABLE_PATH, /sys/class/qcom-battery/reverse_chg_mode)
 
 # Properties
 TARGET_ODM_PROP += $(COMMON_PATH)/properties/odm.prop