USEify USES=php.

The following variables have been folded into arguments:

• USE_PHPIZE -> USES=php:phpize
• USE_PHPEXT -> USES=php:ext
• USE_ZENDEXT -> USES=php:zend
• USE_PHP_BUILD -> USES=php:build
• WANT_PHP_CLI -> USES=php:cli
• WANT_PHP_CGI -> USES=php:cgi
• WANT_PHP_MOD -> USES=php:mod
• WANT_PHP_WEB -> USES=php:web
• WANT_PHP_EMB -> USES=php:embed

PR: 210529
Submitted by: mat
Exp-run by: antoine
Sponsored by: Absolight
Differential Revision: https://reviews.freebsd.org/D6936