Makefile: Drop unused, broken target recurse-fuzz

Target recurse-fuzz depends on pc-bios/optionrom/fuzz, which can't be
made.  It's not used anywhere.  Added in commit c621dc3e, looks
like cargo cult.  Delete.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20200424071142.3525-2-armbru@redhat.com>
Reviewed-by: NAlexander Bulekov <alxndr@bu.edu>

Makefile

@@ -582,7 +582,6 @@ $(ROM_DIRS_RULES):
 
 .PHONY: recurse-all recurse-clean recurse-install
 recurse-all: $(addsuffix /all, $(TARGET_DIRS) $(ROM_DIRS))
-recurse-fuzz: $(addsuffix /fuzz, $(TARGET_DIRS) $(ROM_DIRS))
 recurse-clean: $(addsuffix /clean, $(TARGET_DIRS) $(ROM_DIRS))
 recurse-install: $(addsuffix /install, $(TARGET_DIRS))
 $(addsuffix /install, $(TARGET_DIRS)): all