udev: Drop hwrng rules

udev: Drop hwrng rules

This is another fragment of rngd - the gift that keeps giving.

The udev rules file contains a lot of stuff for a prototype which never
went into production. So, that can be dropped.

It would have been left with one rule that starts rngd whenever a HWRNG
is being found. That is however no longer needed as rngd is being
started in the init process. We no longer need to initialize it as early
as possible to seed the kernel's PRNG.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>