Corrected the layer in getVal8

Author: PaulZC

src/SparkFun_Ublox_Arduino_Library.cpp

@@ -1347,8 +1347,19 @@ uint8_t SFE_UBLOX_GPS::getVal8(uint32_t key, uint8_t layer, uint16_t maxWait)
   for (uint8_t x = 0; x < packetCfg.len; x++)
     packetCfg.payload[x] = 0;
 
+  //VALGET uses different memory layer definitions to VALSET
+  //because it can only return the value for one layer.
+  //So we need to fiddle the layer here.
+  //And just to complicate things further, the ZED-F9P only responds
+  //correctly to layer 0 (RAM) and layer 7 (Default)!
+  uint8_t getLayer = 7; // 7 is the "Default Layer"
+  if ((layer & VAL_LAYER_RAM) == VAL_LAYER_RAM) // Did the user request the RAM layer?
+  {
+    getLayer = 0; // Layer 0 is RAM
+  }
+
   payloadCfg[0] = 0;     //Message Version - set to 0
-  payloadCfg[1] = layer; //By default we ask for the BBR layer
+  payloadCfg[1] = getLayer; //Layer
 
   //Load key into outgoing payload
   payloadCfg[4] = key >> 8 * 0; //Key LSB