board: stm32f746-disco: drop board_late_init()

The removal of the "st,button1" and "st,led1" compatibles has emptied
the board_late_init(), so let's remove it along with the configuration
that allows its invocation.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
5 files changed