Remove .comp files from docs/src

[hansu]

There are two .comp files in docs/src/hal which are also in comp.adoc as examples for halcompile.
out8.comp can be safely deleted but rand.comp is used in tests:

linuxcnc/tests/Submakefile

Lines 19 to 21 in e90c66d

	../tests/halcompile/userspace/rand_test.comp: \
	../docs/src/hal/rand.comp
	sed $< -e "1 s/rand/rand_test/" > $@

I think it does not belong in docs/ and should be moved to tests/ or somewhere else.

[grandixximo]

Are you patching this?

[hansu]

Happy to accept a patch :-)