disk-image-{minimal,mfs-root}: Don't override kern.random.harvest.mask

This drops software entropy sources and results in RNG-less FPGA
environments severely lacking any usable entropy. Whilst improving
performance is useful, doing so at the expense of actually working is
not.

Author: jrtc27

pycheribuild/files/minimal-image/etc/sysctl.conf

@@ -6,6 +6,3 @@ machdep.unaligned_log_pps_limit=0
 
 # Large core dumps and slow SDCards don't mix.
 kern.coredump=0
-
-# Don't collect entropy from software interupts (saves ~2% from intr on DE4)
-kern.random.harvest.mask=767