Enable multiread by default for LIS3MDL since using I2C interface
the subaddr Msb is used to automatically increase the slave address
during multiple data read/write. In the same way, using SPI interface,
bit 1 in register address is used to enable auto-increment of the slave
address in multiple read/write.

Fixes: 872e79ad (iio:magn: Add STMicroelectronics magn driver)
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>