Race condition on repeat request and repeat ack

[nakarlsson]

Possible race condition on ESC repeat request and PDI repeat ack.

When running CTT and mailbox tests for repeat request 1 & 2 in a sequence on slow targets, the test might make repeat ack to indicate that toogle and backup mailbox is in place when it actually isn't. instead it is the previous value on PDI repeat ack that isn't yet updated due to slow reaction on SM change interrupt.