modules: update OpenWrt

6fc02f2a45 OpenWrt v19.07.6: revert to branch defaults
b12284a14c OpenWrt v19.07.6: adjust config defaults
8055e38794 dnsmasq: Backport some security updates
733e62a8e1 uboot-at91: Add PKG_MIRROR_HASH to fix download
53814dadaf at91bootstrap: Add PKG_MIRROR_HASH to fix download
e30d3ea95f mbedtls: update to 2.16.9
c7b9c85819 kernel: bump 4.14 to 4.14.215
c9388fa986 kernel: bump 4.14 to 4.14.214
e290024717 glibc: update to latest 2.27 commit
2c37993c8a build/prereq: merge ifndef IB block together
79b1fa1702 build, imagebuilder: Do not require compilers
58138df2d5 build, imagebuilder: Do not require libncurses-dev
42e478eb0d build/json: add filesystem information