Change the x86_64-specific dracut configuration of RHEL-8.5 and RHEL-9.0
EC2 and AMI images to not include `xen-netfront` driver and add `nvme`
driver, which was previously not included. Since the configuration is no
longer Xen-specific, rename the configuration file to `ec2.conf`.
Justification:
There is no reason to put `xen-netfront` to initramfs as EC2 images don't
boot from network root. In addition, add `nvme` driver to handle the case
when initramfs is getting forcefully rebuild on a Xen instance (and not able
to boot on Nitro after that).
Related to https://issues.redhat.com/browse/COMPOSER-1096.
Signed-off-by: Tomas Hozza <thozza@redhat.com>