hmc5883: fixed DEVIOCGDEVICEID ioctl

we need to pass the ioctl through to the bus interface

thanks to Jon Challinger for noticing this bug

src/drivers/hmc5883/hmc5883.cpp

@@ -66,6 +66,7 @@
 #include <drivers/drv_mag.h>
 #include <drivers/drv_hrt.h>
 #include <drivers/device/ringbuffer.h>
+#include <drivers/drv_device.h>
 
 #include <uORB/uORB.h>
 #include <uORB/topics/subsystem_info.h>
@@ -725,6 +726,9 @@ HMC5883::ioctl(struct file *filp, int cmd, unsigned long arg)
 		debug("MAGIOCGEXTERNAL in main driver");
 		return _interface->ioctl(cmd, dummy);
 
+	case DEVIOCGDEVICEID:
+		return _interface->ioctl(cmd, dummy);
+
 	default:
 		/* give it to the superclass */
 		return CDev::ioctl(filp, cmd, arg);

src/drivers/hmc5883/hmc5883_i2c.cpp

@@ -53,6 +53,7 @@
 
 #include <drivers/device/i2c.h>
 #include <drivers/drv_mag.h>
+#include <drivers/drv_device.h>
 
 #include "hmc5883.h"
 
@@ -90,6 +91,7 @@ HMC5883_I2C_interface(int bus)
 HMC5883_I2C::HMC5883_I2C(int bus) :
 	I2C("HMC5883_I2C", nullptr, bus, HMC5883L_ADDRESS, 400000)
 {
+	_device_id.devid_s.devtype = DRV_MAG_DEVTYPE_HMC5883;
 }
 
 HMC5883_I2C::~HMC5883_I2C()
@@ -117,6 +119,9 @@ HMC5883_I2C::ioctl(unsigned operation, unsigned &arg)
 			return 0;
 		}
 
+	case DEVIOCGDEVICEID:
+		return CDev::ioctl(nullptr, operation, arg);
+
 	default:
 		ret = -EINVAL;
 	}

src/drivers/hmc5883/hmc5883_spi.cpp

@@ -53,6 +53,7 @@
 
 #include <drivers/device/spi.h>
 #include <drivers/drv_mag.h>
+#include <drivers/drv_device.h>
 
 #include "hmc5883.h"
 #include <board_config.h>
@@ -92,6 +93,7 @@ HMC5883_SPI_interface(int bus)
 HMC5883_SPI::HMC5883_SPI(int bus, spi_dev_e device) :
 	SPI("HMC5883_SPI", nullptr, bus, device, SPIDEV_MODE3, 11*1000*1000 /* will be rounded to 10.4 MHz */)
 {
+	_device_id.devid_s.devtype = DRV_MAG_DEVTYPE_HMC5883;
 }
 
 HMC5883_SPI::~HMC5883_SPI()
@@ -146,6 +148,9 @@ HMC5883_SPI::ioctl(unsigned operation, unsigned &arg)
 			return 0;
 		}
 
+	case DEVIOCGDEVICEID:
+		return CDev::ioctl(nullptr, operation, arg);
+
 	default:
 	{
 		ret = -EINVAL;