gnss(septentrio): fix incorrect heading offset configuration

Heading offset was configured as radians but should be configured as
degrees on Septentrio receivers. The parameter was already in degrees
but the configuration logic was changing it into radians. Also allow the
entire allowed range of heading offset values for Septentrio receivers.

src/drivers/gnss/septentrio/module.yaml

@@ -71,7 +71,7 @@ parameters:
         type: float
         decimal: 3
         default: 0
-        min: 0
+        min: -360
         max: 360
         unit: deg
         reboot_required: true

src/drivers/gnss/septentrio/septentrio.cpp

@@ -153,8 +153,6 @@ SeptentrioDriver::SeptentrioDriver(const char *device_path, Instance instance, u
 	// Enforce null termination.
 	_port[sizeof(_port) - 1] = '\0';
 
-	reset_gps_state_message();
-
 	int32_t enable_sat_info {0};
 	get_parameter("SEP_SAT_INFO", &enable_sat_info);
 
@@ -211,6 +209,8 @@ SeptentrioDriver::SeptentrioDriver(const char *device_path, Instance instance, u
 	}
 
 	set_device_type(DRV_GPS_DEVTYPE_SBF);
+
+	reset_gps_state_message();
 }
 
 SeptentrioDriver::~SeptentrioDriver()
@@ -948,7 +948,7 @@ SeptentrioDriver::ConfigureResult SeptentrioDriver::configure()
 	}
 
 	// Specify the offsets that the receiver applies to the computed attitude angles.
-	snprintf(msg, sizeof(msg), k_command_set_attitude_offset, (double)(_heading_offset * 180 / M_PI_F), (double)_pitch_offset);
+	snprintf(msg, sizeof(msg), k_command_set_attitude_offset, static_cast<double>(_heading_offset), static_cast<double>(_pitch_offset));
 
 	if (!send_message_and_wait_for_ack(msg, k_receiver_ack_timeout_fast)) {
 		return ConfigureResult::FailedCompletely;