dracut.sh, dracut-functions.sh: do lazy kernel module dep resolving

dracut.sh, dracut-functions.sh: do lazy kernel module dep resolving

First, we just install the kernel module and keep track, what we
installed. At the very end, call modprobe and modinfo for firmwares to
resolve all kernel module dependencies. This speeds up image creation,
because we can call modprobe and modinfo with many modules.