ARM: DTS: stm32: add pwrcfg node for stm32f746

This node is needed to enable performance mode
when system frequency is set up to 200Mhz.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Vikas Manocha <vikas.manocha@st.com>
2 files changed