usbcamera: initial implementation of default usb camera HAL

* Basic skeleton of usb camera hal implementation
* Vendor tag is not supported yet
* Further usb camera hal implementation can be filled into UsbCamera.cpp
* Hot plug thread need to be implemented

Change-Id: Ida63b6d640e32192f5b60a280d9d5106d80e523f
diff --git a/modules/Android.mk b/modules/Android.mk
index 0725d3e..13a0b5b 100644
--- a/modules/Android.mk
+++ b/modules/Android.mk
@@ -1,4 +1,4 @@
 hardware_modules := gralloc hwcomposer audio nfc nfc-nci local_time \
-	power usbaudio audio_remote_submix camera consumerir sensors vibrator \
+	power usbaudio audio_remote_submix camera usbcamera consumerir sensors vibrator \
 	tv_input fingerprint
 include $(call all-named-subdir-makefiles,$(hardware_modules))