usf: Include usf_product.mk for USF PDK.

Bug: 237953890
Test: Compile pass. Verified sensor list & sampling on R4.
      The validation is done both on PDK build and tm-qpr-dev build.
Signed-off-by: Rick Chen <rickctchen@google.com>
Change-Id: Iff49dc63e1a3601dd254c292504aaf32dec79687
diff --git a/device.mk b/device.mk
index e7af97e..3ea32c3 100644
--- a/device.mk
+++ b/device.mk
@@ -941,7 +941,11 @@
 #$(call inherit-product-if-exists, hardware/google_devices/gs101/gs101.mk)
 #$(call inherit-product-if-exists, vendor/google_devices/common/exynos-vendor.mk)
 #$(call inherit-product-if-exists, hardware/broadcom/wlan/bcmdhd/firmware/bcm4375/device-bcm.mk)
+ifeq ($(wildcard vendor/google/sensors/usf),)
+$(call inherit-product-if-exists, vendor/google_devices/gs101/proprietary/usf/usf_product.mk)
+else
 $(call inherit-product-if-exists, vendor/google/sensors/usf/android/usf_efw_product.mk)
+endif
 $(call inherit-product-if-exists, vendor/google/services/LyricCameraHAL/src/build/device-vendor.mk)
 $(call inherit-product-if-exists, vendor/google/camera/devices/whi/device-vendor.mk)