u-boot: Add missing dependency on flex and bison native
The U-Boot build, in particular the Kconfig, depends on bison and
flex native. Add the missing dependencies.
Signed-off-by: Marek Vasut <marex@denx.de> Cc: Alexander Kanavin <alexander.kanavin@linux.intel.com> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Richard Purdie <richard.purdie@linuxfoundation.org> Cc: Ross Burton <ross.burton@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
