rockminer: Limit even unsafe frequencies to 640 MHz, since above that overflows frequency bits and triggers fan control
tq_pop: Remove abstime argument since nothing used it and it wouldn't work anyway (uses CLOCK_REALTIME while we use CLOCK_MONOTONIC[_RAW] when possible)
Bugfix: rockminer: Fix processor disabling
Merge commit '105489a' into bfgminer-4.7.x
Merge branch 'rockminer' into bfgminer-4.7.x
Bugfix: Need signed types for ntime min/max offsets

Conflicts:
	miner.h