tests: arm: adjust test for relocated rom

Add a memory barrier to make sure write to NVIC is completed
before continuing with the test fails in scenarios where
CONFIG_ROMSTART_RELOCATION_ROM is enabled for boards like MPS3
Corstone310 and k_sem_take is called before the isr's are called.

Signed-off-by: Sudan Landge <sudan.landge@arm.com>
1 file changed