https://serverfault.com/questions/709433/install-a-newer-version-of-git-on-centos-7
You could use a IUS repository (https://ius.io/) as provided on Git official site here: https://git-scm.com/download/linux
To do that, run (as root):
yum install epel-release yum remove git rpm -U https://centos7.iuscommunity.org/ius-release.rpm yum install git2u