On Centos 6.5 regular PHP packages work:

[root@vagrant-centos65 vagrant]# php -v
PHP 5.3.3 (cli) (built: Dec 11 2013 03:29:57) 
Copyright (c) 1997-2010 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
[root@vagrant-centos65 vagrant]# mysql --version
mysql  Ver 14.14 Distrib 5.6.17-66.0, for Linux (x86_64) using  EditLine wrapper
[root@vagrant-centos65 vagrant]# rpm -qa Percona-Server-shared-56 --provides
libmysqlclient.so.18()(64bit)  
libperconaserverclient.so.18()(64bit)  
libperconaserverclient.so.18(libperconaserverclient_18)(64bit)  
Percona-Server-shared-56 = 5.6.17-rel66.0.el6
Percona-Server-shared-56(x86-64) = 5.6.17-rel66.0.el6

But when remi repository is installed and try to do a yum update I get the following:

[root@vagrant-centos65 vagrant]# yum update
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirror.linux.duke.edu
 * epel: mirror.cogentco.com
 * extras: mirror.linux.duke.edu
 * remi: mirrors.mediatemple.net
 * updates: centost5.centos.org
Setting up Update Process
Resolving Dependencies
--> Running transaction check
---> Package php.x86_64 0:5.3.3-27.el6_5 will be updated
---> Package php.x86_64 0:5.4.29-3.el6.remi will be an update
---> Package php-cli.x86_64 0:5.3.3-27.el6_5 will be updated
---> Package php-cli.x86_64 0:5.4.29-3.el6.remi will be an update
---> Package php-common.x86_64 0:5.3.3-27.el6_5 will be updated
---> Package php-common.x86_64 0:5.4.29-3.el6.remi will be an update
---> Package php-fpm.x86_64 0:5.3.3-27.el6_5 will be updated
---> Package php-fpm.x86_64 0:5.4.29-3.el6.remi will be an update
---> Package php-mysql.x86_64 0:5.3.3-27.el6_5 will be updated
---> Package php-mysql.x86_64 0:5.4.29-3.el6.remi will be an update
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: php-mysql-5.4.29-3.el6.remi.x86_64
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_16)(64bit) for package: php-mysql-5.4.29-3.el6.remi.x86_64
---> Package php-pdo.x86_64 0:5.3.3-27.el6_5 will be updated
---> Package php-pdo.x86_64 0:5.4.29-3.el6.remi will be an update
--> Running transaction check
---> Package Percona-XtraDB-Cluster-shared-56.x86_64 1:5.6.15-25.5.759.rhel6 will be installed
--> Processing Conflict: 1:Percona-XtraDB-Cluster-shared-56-5.6.15-25.5.759.rhel6.x86_64 conflicts Percona-Server-shared-56
--> Finished Dependency Resolution
Error: Percona-XtraDB-Cluster-shared-56 conflicts with Percona-Server-shared-56-5.6.17-rel66.0.el6.x86_64
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

However, if I remove Percona Server 56 and disable Percona repo then run a yum update then install PS 5.6 back then everything works.
[root@vagrant-centos65 vagrant]# php -v
PHP 5.4.29 (cli) (built: Jun  5 2014 16:07:48) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies

[root@vagrant-centos65 vagrant]# rpm -q Percona-Server-shared-56 --provides
libmysqlclient.so.18()(64bit)  
libperconaserverclient.so.18()(64bit)  
libperconaserverclient.so.18(libperconaserverclient_18)(64bit)  
Percona-Server-shared-56 = 5.6.17-rel66.0.el6
Percona-Server-shared-56(x86-64) = 5.6.17-rel66.0.el6