Apply changes which significantly speed up cache operations.
Removed k_busy_wait from function which polls for cache busyness.
Removed spinlock from cache operation. Lock taking and releasing
takes time and it is faster to check if LINEADDR changed
after performing the operation. If LINEADDR changed then it
indicates that current context was preempted by another cache
operation. If such state is detected current operation is
repeated.
Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>