aml-util: Disable usb_monitor when USE_USB_MONITOR is n. [2/2]

PD#SWPL-168567

Problem:
usb_monitor is not necessary for android 5.1.1.

Solution:
Disable usb_monitor when USE_USB_MONITOR is n.

Verify:
AV400

Change-Id: I64b80dd7b077183d14b771d95f931ba9e986bc58
Signed-off-by: hanliang.xiong <hanliang.xiong@amlogic.com>
diff --git a/utils/Makefile b/utils/Makefile
index 6c12fdf..5223bd9 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -1,5 +1,5 @@
 OUT_DIR ?= .
-UTILS = wifi_power multi_wifi_load_driver input_eventd usbpower usbtestpm usbtestpm_mx usbtestpm_mx_iddq usbpower_mx_iddq usb_monitor vad_service
+UTILS = wifi_power multi_wifi_load_driver input_eventd usbpower usbtestpm usbtestpm_mx usbtestpm_mx_iddq usbpower_mx_iddq vad_service
 ifeq ($(USE_SIMULATE_KEY),y)
 UTILS += simulate_key
 endif
@@ -9,10 +9,16 @@
 ifeq ($(USE_BATTERY_MONITOR),y)
 UTILS += battery_monitor
 endif
+
 ifeq ($(USE_UAC_HID),y)
 UTILS += uac_hid
 endif
 
+# if USE_USB_MONITOR is empty, it means y
+ifneq ($(USE_USB_MONITOR),n)
+UTILS += usb_monitor
+endif
+
 .PHONY: all install clean
 #CFLAGS += $(AML_UTIL_PRIV_FLAGS)