Extend checks on build prerequisites for building OpenWRT core

Extend checks on build prerequisites for building OpenWRT core

OpenWRT requires a number of Perl modules to be installed. It wasn't checking on all of them.
This patch adds checks for Perl FindBin, File::Copy, File::Compare and Thread::Queue modules.

Failing to install these, will have the build break at some point. By adding these to the
prereq-build.mk script, they are checked on forehand.

Tested on a Fedora 33 and 34 (beta) that was freshly installed. Fedora appears to
break up Perl modules into small packages that need to be installed for the build to succeed.

Signed-off-by: Bas Mevissen <abuse@basmevissen.nl>