Platform: stm32l5xx: Set all NVIC interrupt target to NS

The STM32L5xx does not support NVIC in secure at the moment, just align
with other existing platforms that target all NVIC interrupt to NS.

Change-Id: I32c56ba36a88656df51969352876c45453ebcfee
Signed-off-by: Karl Zhang <karl.zhang@arm.com>
3 files changed