GNSS: Support setInterval cycle of less than 1 second

Add setInterval method to support cycles of less than 1 second.
The cycle can select from SpIntervalFreq enumeration type.

Arduino15/packages/SPRESENSE/hardware/spresense/1.0.0/libraries/GNSS/GNSS.cpp

@@ -775,6 +775,33 @@ int SpGnss::setInterval(long interval)
     return ret;
 }
 
+/**
+ * @brief Set the pos interval time
+ * @details Set interval of POS operation.
+ * @param [in] Interval time[sec]
+ * @return 0 if success, -1 if failure
+ */
+int SpGnss::setInterval(SpIntervalFreq interval)
+{
+    int ret;
+    struct cxd56_gnss_ope_mode_param_s setdata;
+
+    /* Set parameter. */
+
+      setdata.mode     = 1;
+      setdata.cycle    = (uint32_t)interval;
+
+    /* Call ioctl. */
+
+    ret = ioctl(fd_, CXD56_GNSS_IOCTL_SET_OPE_MODE, (unsigned long)&setdata);
+    if (ret < OK)
+    {
+        PRINT_E("SpGnss E: Failed to set Interval\n");
+    }
+
+    return ret;
+}
+
 /**
  * @brief Returns whether the specified satellite system is selecting
  * @return 1 use, 0 unuse

Arduino15/packages/SPRESENSE/hardware/spresense/1.0.0/libraries/GNSS/GNSS.h

@@ -99,6 +99,19 @@ enum SpSatelliteType {
     UNKNOWN   = 0,
 };
 
+/**
+ * @enum SpIntervalFreq
+ * @brief Interval frequency
+ */
+enum SpIntervalFreq {
+    SpInterval_10Hz = 100,
+    SpInterval_8Hz  = 125,
+    SpInterval_5Hz  = 200,
+    SpInterval_4Hz  = 250,
+    SpInterval_2Hz  = 500,
+    SpInterval_1Hz  = 1000,
+};
+
 /**
  * @class SpGnssTime
  * @brief Time acquired from the satellite at the time of positioning
@@ -358,6 +371,14 @@ class SpGnss
      */
     int setInterval(long interval = 1);
 
+    /**
+     * @brief Set the pos interval time
+     * @details Set interval of POS operation.
+     * @param [in] interval Interval frequency
+     * @return 0 if success, -1 if failure
+     */
+    int setInterval(SpIntervalFreq interval);
+
     /**
      * @brief Returns whether the specified satellite system is selecting
      * @details Returns whether satellite system specified as argument is