tools/flex: Revert "tools/flex: add autoreconf"

This was already done in commit 91e262c ("tools: flex: fix build
with automake 1.15.1")

This reverts commit 6b127d8.

Signed-off-by: Hauke Mehrtens <[email protected]>

Author: hauke

tools/flex/Makefile

@@ -15,7 +15,6 @@ PKG_HASH:=e87aae032bf07c26f85ac0ed3250998c37621d95f8bd748b31f15b33c45ee995
 
 HOST_FIXUP:=autoreconf
 HOST_BUILD_PARALLEL:=1
-HOST_FIXUP:=autoreconf
 
 include $(INCLUDE_DIR)/host-build.mk