[build] Explicitly link efilink against -liberty

On some systems, libbfd is supplied only as a static library; linking
will fail unless -liberty is also specified.

src/Makefile.housekeeping

 #
 $(EFILINK) : util/efilink.c $(MAKEDEPS)
 	$(QM)$(ECHO) "  [HOSTCC] $@"
-	$(Q)$(HOST_CC) -O2 -o $@ $< -lbfd
+	$(Q)$(HOST_CC) -O2 -o $@ $< -lbfd -liberty
 CLEANUP += $(EFILINK)
 
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