Add required rotation option to driver startup command and fix a couple of details in warnings/comments

src/drivers/drv_input_capture.h

@@ -60,7 +60,7 @@ typedef void (*capture_callback_t)(void *context, uint32_t chan_index,
 				   hrt_abstime edge_time, uint32_t edge_state, uint32_t overflow);
 
 /**
- * Maximum number of PWM output channels supported by the device.
+ * Maximum number of PWM input channels supported by the device.
  */
 #ifndef INPUT_CAPTURE_MAX_CHANNELS
 #define INPUT_CAPTURE_MAX_CHANNELS 6

src/drivers/hmc5883/hmc5883.cpp

@@ -1102,7 +1102,7 @@ int HMC5883::calibrate(struct file *filp, unsigned enable)
 
 	/* start the sensor polling at 50 Hz */
 	if (OK != ioctl(filp, SENSORIOCSPOLLRATE, 50)) {
-		warn("FAILED: SENSORIOCSPOLLRATE 2Hz");
+		warn("FAILED: SENSORIOCSPOLLRATE 50Hz");
 		ret = 1;
 		goto out;
 	}

src/drivers/lis3mdl/lis3mdl.cpp

@@ -35,6 +35,8 @@
  * @file lis3mdl.cpp
  *
  * Driver for the LIS3MDL magnetometer connected via I2C or SPI.
+ *
+ * Based on the hmc5883 driver.
  */
 
 #include <px4_config.h>