arm64: dts: qcom: msm8916-samsung-a2015: Add accelerometer/magnetometer

A3U/A5U both use a Bosch BMC150 accelerometer/magnetometer combo.
The chip provides two separate I2C devices for the accelerometer
and magnetometer that are already supported by the bmc150-accel
and bmc150-magn driver.

The only difference between A3U/A5U is the way the sensor is
mounted on the mainboard - set the mount-matrix in the
device-specific device tree part to handle that difference.

Co-developed-by: Michael Srba <michael.srba@seznam.cz>
Signed-off-by: Michael Srba <michael.srba@seznam.cz>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20200622151751.408995-5-stephan@gerhold.net
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>