sensor/stmemsc: Align stmemsc i/f to v2.3

Align stmemsc HAL i/f to v2.3

Moreover following fix has been now implemented, that will be incorporated
in next STdC version:

  - lsm6dso_STdC: fix -Wmaybe-uninitialized warning in lsm6dso_mode_set() API

Signed-off-by: Armando Visconti <armando.visconti@st.com>