lang/php??: make CONFLICTS_INSTALL visible to PHP module ports

The definition of CONFLICTS_INSTALL already included ${PKGNAMESUFFIX},
but in a block that was conditional on ${PKGNAMESUFFIX} not being
defined, defying the purpose.

After this change all ports that refer to the lang/php?? interpreter
ports get an automatic CONFLICTS_INSTALL definition that prevents the
installation of the same module for multiple interpreter versions.

This change adds correct CONFLICTS_INSTALL definitions to hundreds of
PHP ports that previously lacked any such definition.

PHP modules can override this generated CONFLICTS_INSTALL definition
in their Makefiles, if required.

Approved by: portmgr (implicit)