iio:accel:mma8452: drop double include

One inclusion of linux/iio/trigger_consumer.h is sufficient.

Fixes: 	ae6d9ce0 ("iio: mma8452: Add support for interrupt driven triggers.")
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>