greybus: camera: Remove reference to ara subdevice

Remove last occurrence of "ara" term in camera driver.
Replace reference to "ara subdevice" with "gmp subdevice"
Signed-off-by: Jacopo Mondi <jacopo.mondi@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/camera.c

@@ -848,7 +848,7 @@ static int gb_camera_request_handler(struct gb_operation *op)
 }
 
 /* -----------------------------------------------------------------------------
- * Interface with HOST ara camera.
+ * Interface with HOST gmp camera.
  */
 static unsigned int gb_camera_mbus_to_gb(enum v4l2_mbus_pixelcode mbus_code)
 {