flux-ota.bbclass: add os-release to IMAGE_INSTALL
flux-ota.bbclass: add os-release to IMAGE_INSTALL

It's being required when making otaimg.

Signed-off-by: Ming Liu <070ee461bca4578ddd34d91eec07d1f455f3cdee@gmail.com>

fluxos-iot/meta-flux,fluxos-iot/meta-flux,fluxos-iot/meta-flux