Add buildroot-2019.02-gcc7.4.0-cortexA5 packet

guowenxue

2019-08-11 18ef44bea44d9a27108027991a5071cd1d90dfea

linux-bsp/tarballs/linux-at91.tar.xz does not exist in tree 4ccd62127677dfaa570c030c763ee34ba64097d5