findutils: add dependency on bison

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

Backport of r43064

git-svn-id: svn://svn.openwrt.org/openwrt/branches/barrier_breaker@43065 3c298f89-4303-0410-b956-a3cf2f4a3e73

tools/Makefile

@@ -72,6 +72,7 @@ $(curdir)/b43-tools/compile := $(curdir)/bison/install
 $(curdir)/padjffs2/compile := $(curdir)/findutils/install
 $(curdir)/cloog/compile := $(curdir)/ppl/install
 $(curdir)/bc/compile := $(curdir)/bison/install
+$(curdir)/findutils/compile := $(curdir)/bison/install
 
 ifneq ($(CONFIG_CCACHE),)
 $(foreach tool, $(tools-y), $(eval $(curdir)/$(tool)/compile += $(curdir)/ccache/install))