Added PA1616S GPS module (#5157)

* Added GPS chip PA1616S

GPS chip PA1616S is used in some recent Adafruit GPS breakout boards.

* Update GPS.cpp

---------

Co-authored-by: picusviridis <mesh.culprit381@passmail.net>

src/gps/GPS.h

@@ -34,6 +34,7 @@ typedef enum {
     GNSS_MODEL_UC6580,
     GNSS_MODEL_UNKNOWN,
     GNSS_MODEL_MTK_L76B,
+    GNSS_MODEL_MTK_PA1616S,
     GNSS_MODEL_AG3335,
     GNSS_MODEL_AG3352
 } GnssModel_t;