doc: build: TEXIDEP: Recognize verbatim includes

  When generating the .dep files for .texi sources, verbatim includes
(@verbatiminclude) should also be taken into account.
Signed-off-by: Alexander Strasser <eclipse7@gmx.net>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

doc/Makefile

@@ -21,7 +21,7 @@ all-$(CONFIG_DOC): documentation
 
 documentation: $(DOCS)
 
-TEXIDEP = awk '/^@include/ { printf "$@: $(@D)/%s\n", $$2 }' <$< >$(@:%=%.d)
+TEXIDEP = awk '/^@(verbatim)?include/ { printf "$@: $(@D)/%s\n", $$2 }' <$< >$(@:%=%.d)
 
 doc/%.txt: TAG = TXT
 doc/%.txt: doc/%.texi