util/lint: Update spelling.txt, add makefile to sort it

- Update spelling.txt with Lintian changes
- Remove words that are going to mess up code
- Add comments to the header about what words should be removed, along
with where the files
- Add Makefile to sort the list

Note that this undoes some of the sorting that Patrick introduced in
commit CB:38632 - ID: 805b291830
I just cannot reproduce his sort order, even using the script he put
into the commit message.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Ic131d5b08409f43eb700dcc8f125af00cff53d71
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64893
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/lint/Makefile

@@ -0,0 +1,6 @@
+sort: sort-spelling.txt
+
+sort-%: %
+	csplit --prefix $<- $< '/^$$/'
+	LC_ALL="en_US.UTF-8" LANG= sort -u $<-01 | cat $<-00 - > $<
+	rm -f $<-0[01]