Changes

bts: TC_pcu_{rts_req,time_ind}: Relax expectancies on rx primitive count

Even with latest changes I can still sometimes run into up to 6 FNs less
than the currently minimum expected. That's usually 1-2 primitives less,
which in the number of >100 we are receiving over 5 seconds, seems like
a plausible drift.

Change-Id: I887bd80a90e3ef8142cc29acde2ac9a3ea4869d6