boards: mps2_an521: select SOC_MPS2_AN521_CPU0 in mps2 targets on CPU0

Select Kconfig option SOC_MPS2_AN521_CPU0 in board
definitions of MPS2 AN521 targets which build on
CPU0 of the MPS2 AN521. This is the case for the
mps2_an521 and mps2_an521_nonsecure targets.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2 files changed