Add Support for NVMe EC2 Instances (m5, c5)

[stanvarlamov]

As OpenShift 3.9 is now fully compatible with ec2 m5 instances - those can be used in the configuration, after this proposed setup-master.sh and setup-node-sh update:

Replace

cat <<EOF > /etc/sysconfig/docker-storage-setup
DEVS=/dev/xvdf
VG=docker-vg
EOF

with

DEVICE_NAME=xvdf
lsblk | grep -q "xvdf"
if [ $? -ne 0 ]; then
   DEVICE_NAME=nvme1n1
fi   
cat <<EOF > /etc/sysconfig/docker-storage-setup
DEVS=/dev/$DEVICE_NAME
VG=docker-vg
EOF

[dwmkerr]

Looks great @stanvarlamov, I'll hopefully get onto this shortly