configs/stm32mp157*: uboot needs openssl
Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/1746850755
https://gitlab.com/buildroot.org/buildroot/-/jobs/1746850753
https://gitlab.com/buildroot.org/buildroot/-/jobs/1746850754
Signed-off-by: Bartosz Bilas <b.bilas@grinn-global.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>