soong: Unset custom charging path var if it is not defined

Change-Id: I9de31c8aff5b17932f0de23026aebf95166c5163

config/BoardConfigSoong.mk

@@ -34,7 +34,6 @@ SOONG_CONFIG_lineageGlobalVars += \
     gralloc_handle_has_custom_content_md_reserved_size \
     gralloc_handle_has_reserved_size \
     gralloc_handle_has_ubwcp_format \
-    target_health_charging_control_charging_path \
     target_health_charging_control_charging_enabled \
     target_health_charging_control_charging_disabled \
     target_health_charging_control_deadline_path \
@@ -52,6 +51,11 @@ SOONG_CONFIG_lineageGlobalVars += \
     target_trust_usb_control_disable \
     uses_egl_display_array
 
+ifneq ($(TARGET_HEALTH_CHARGING_CONTROL_CHARGING_PATH),)
+SOONG_CONFIG_lineageGlobalVars += \
+    target_health_charging_control_charging_path
+endif
+
 SOONG_CONFIG_NAMESPACES += lineageNvidiaVars
 SOONG_CONFIG_lineageNvidiaVars += \
     uses_nvidia_enhancements
@@ -107,7 +111,9 @@ TARGET_TRUST_USB_CONTROL_DISABLE ?= 0
 # Soong value variables
 SOONG_CONFIG_lineageGlobalVars_additional_gralloc_10_usage_bits := $(TARGET_ADDITIONAL_GRALLOC_10_USAGE_BITS)
 SOONG_CONFIG_lineageGlobalVars_bootloader_message_offset := $(BOOTLOADER_MESSAGE_OFFSET)
+ifneq ($(TARGET_HEALTH_CHARGING_CONTROL_CHARGING_PATH),)
 SOONG_CONFIG_lineageGlobalVars_target_health_charging_control_charging_path := $(TARGET_HEALTH_CHARGING_CONTROL_CHARGING_PATH)
+endif
 SOONG_CONFIG_lineageGlobalVars_target_health_charging_control_charging_enabled := $(TARGET_HEALTH_CHARGING_CONTROL_CHARGING_ENABLED)
 SOONG_CONFIG_lineageGlobalVars_target_health_charging_control_charging_disabled := $(TARGET_HEALTH_CHARGING_CONTROL_CHARGING_DISABLED)
 SOONG_CONFIG_lineageGlobalVars_target_health_charging_control_deadline_path := $(TARGET_HEALTH_CHARGING_CONTROL_DEADLINE_PATH)