do not check for libdl on freebsd, check for phreads in libc_r on freebsd.
do not check for libdl on freebsd, check for phreads in libc_r on freebsd.

lancebaiyouview/DirectFB,deniskropp/DirectFB,sklnet/DirectFB,deniskropp/DirectFB,lancebaiyouview/DirectFB,DirectFB/directfb,kevleyski/DirectFB-1,jcdubois/DirectFB,lancebaiyouview/DirectFB,mtsekm/test,djbclark/directfb-core-DirectFB,dfbdok/DirectFB1,DirectFB/directfb,sklnet/DirectFB,lancebaiyouview/DirectFB,kevleyski/DirectFB-1,dfbdok/DirectFB1,DirectFB/directfb,kaostao/directfb,Distrotech/DirectFB,jcdubois/DirectFB,dfbdok/DirectFB1,jcdubois/DirectFB,sklnet/DirectFB,kaostao/directfb,kaostao/directfb,kevleyski/directfb,djbclark/directfb-core-DirectFB,kevleyski/DirectFB-1,djbclark/directfb-core-DirectFB,Distrotech/DirectFB,deniskropp/DirectFB,djbclark/directfb-core-DirectFB,deniskropp/DirectFB,sklnet/DirectFB,kevleyski/directfb,mtsekm/test,Distrotech/DirectFB,kevleyski/directfb,mtsekm/test,kevleyski/DirectFB-1,kevleyski/directfb