sensors: lis2dh: support disabling SDO/SA0 pull-up during init

Some chips supported by lis2dh driver (such as LIS2DH12 and LIS3DH)
contain CTRL_REG0 (1Eh) register to control internal pull-up on SDO/SA0
line (enabled by default). Add disconnect-sdo-sa0-pull-up boolean
device-tree property to allow disconnecting pull-up during driver
initialization. This allows to save around 180uA at 3.6V in
accelerometer power-down mode.

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>