Cleanup CentOS pkg

Do not insall from EPEL
install postgresql-devel instead of lbpqxx-devel
install qemu-img-ev instead of qemu-img

Change-Id: I9d0574ec2d13adf672f918e8548606557e0fc654

vars/redhat-7.yml

@@ -21,7 +21,7 @@ cinder_distro_packages:
   - nfs-utils
   - rpcbind
   - libxslt-devel
-  - libpqxx-devel
+  - postgresql-devel
   - kmod-devel
   - kmod-libs
   - zlib-devel
@@ -29,7 +29,7 @@ cinder_distro_packages:
   - iscsi-initiator-utils
 
 cinder_volume_distro_packages:
-  - qemu-img
+  - qemu-img-ev
 
 cinder_lvm_volume_distro_packages:
   - device-mapper-event