samples: blinky pwm running on the nucleo_l4r5zi

Adding an overlay to configure the nucleo_l4r5zi for testing the pwm
blinky application on red led (PB14 on nucleo board)
Each has a specific pwm output from different timers/channels

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