arch: arm: cortex_m: scb: fix MPU code compilation guards

The implementation of `z_arm_clear_arm_mpu_config` was compiled for all
ARM cores that declare to have an MPU. However, we only want to compile
it if the MPU is actually enabled.

Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
1 file changed