[Arm-dev] xfs_growfs step in disk image readme

Hi Jim,

If you're able, I think it would be handy to document using xfs_growfs
in the disk image readme.

## Growing the disk image. 
...
sudo sgdisk -e -d4 -n4:0:0  /dev/<your-device>
xfs_growfs /

I'm not sure if rebooting in between is required or recommended.

1. http://mirror.centos.org/altarch/7/isos/aarch64/ReadMe.txt

Thanks,
Cov
-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code
Aurora Forum, a Linux Foundation Collaborative Project.