http://devdocs.magento.com/guides/v2.0/install-gde/prereq/php-centos.html

Note: mysql_* functions are getting old and they need to be migrated to PDO. See tutorial

These were the base packages installed with PHP 5.4 (before upgrading):

# rpm -qa |grep php | sort
php-5.4.16-36.3.el7_2.x86_64
php-cli-5.4.16-36.3.el7_2.x86_64
php-common-5.4.16-36.3.el7_2.x86_64
php-mbstring-5.4.16-36.3.el7_2.x86_64
php-mcrypt-5.4.16-5.el7.x86_64
php-mysql-5.4.16-36.3.el7_2.x86_64
php-pdo-5.4.16-36.3.el7_2.x86_64

These are the packages after installing PHP 5.6:

# rpm -qa |grep php | sort
php56u-5.6.27-1.ius.centos7.x86_64
php56u-bcmath-5.6.27-1.ius.centos7.x86_64
php56u-cli-5.6.27-1.ius.centos7.x86_64
php56u-common-5.6.27-1.ius.centos7.x86_64
php56u-devel-5.6.27-1.ius.centos7.x86_64
php56u-gd-5.6.27-1.ius.centos7.x86_64
php56u-intl-5.6.27-1.ius.centos7.x86_64
php56u-mbstring-5.6.27-1.ius.centos7.x86_64
php56u-mcrypt-5.6.27-1.ius.centos7.x86_64
php56u-mysqlnd-5.6.27-1.ius.centos7.x86_64
php56u-opcache-5.6.27-1.ius.centos7.x86_64
php56u-pdo-5.6.27-1.ius.centos7.x86_64
php56u-pear-1.10.1-4.ius.centos7.noarch
php56u-pecl-jsonc-1.3.10-2.ius.centos7.x86_64
php56u-pecl-jsonc-devel-1.3.10-2.ius.centos7.x86_64
php56u-process-5.6.27-1.ius.centos7.x86_64
php56u-xml-5.6.27-1.ius.centos7.x86_64

Make a copy of the base /etc/php.ini file and merge in custom settings.