ports/187267: php5-iconv (and php55-iconv) link against converters/libiconv instead of base

[Spil Oss]

Problem is not simply with iconv from base or ports. On 10 php55 was
building against libiconv from base and you could completely remove
the port. SVN rev 341778 re-establishes the dependency on libiconv
from ports for the transliteration capability that is (not yet?)
available in iconv from base (see ports/184596).

.if ${PHP_MODNAME} == "iconv"
CONFIGURE_ARGS+=--with-iconv

USES+= iconv:translit
.endif