evas: build in buffer engine and eet loader statically

evas: build in buffer engine and eet loader statically

These two are always needed according to http://trac.enlightenment.org/e/wiki/Compilation

This should also avoid errors like this:

ERR<1829>:ecore_evas ecore_evas_buffer.c:623 ecore_evas_buffer_allocfunc_new() evas_engine_info_set() init engine 'buffer' failed.

(From meta-openembedded rev: 23fde058b79beb7cf64ed9a9874cde0bb26fcd47)

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Acked-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>