stm32mp: configs: activate the command stm32key only for ST boards

This command is used to evaluate the secure boot on stm32mp SOC,
it is deactivated by default in real products.

We activate this command only in STMicroelectronics defconfig
used with the evaluation boards.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
3 files changed