boot: zephyr: Fix misaligned #else for `irq_lock`

So in PR #1089 I misaligned the `#else` used for the `irq_lock` as it
should be aligned with `CONFIG_MCUBOOT_CLEANUP_ARM_CORE`. So that
`irq_lock`is called when we don't call `__disable_irq` from arm core
clean up code.

Signed-off-by: Sigvart Hovland <sigvart.hovland@nordicsemi.no>
diff --git a/boot/zephyr/main.c b/boot/zephyr/main.c
index 837228b..d2f978a 100644
--- a/boot/zephyr/main.c
+++ b/boot/zephyr/main.c
@@ -201,8 +201,6 @@
 
 #if CONFIG_CPU_HAS_ARM_MPU || CONFIG_CPU_HAS_NXP_MPU
     z_arm_clear_arm_mpu_config();
-#else
-    irq_lock();
 #endif
 
 #if defined(CONFIG_BUILTIN_STACK_GUARD) && \
@@ -214,6 +212,8 @@
     __set_MSPLIM(0);
 #endif
 
+#else
+    irq_lock();
 #endif /* CONFIG_MCUBOOT_CLEANUP_ARM_CORE */
 
 #ifdef CONFIG_BOOT_INTR_VEC_RELOC