boards: arm: stm32l562 disco kit has low power states

The low power states 0∕1∕2 are added to the stm32l562e_dk board
with default min residency values.
The substate-id is mapping the same Zephyr power state.
They correspond to the stm32l562 low power stop0/1/2 modes.

Signed-off-by: Francois Ramu <francois.ramu@st.com>
3 files changed