strat: split out common functionality for future meso use

stratosphere/libstratosphere/source/spl/spl_api.cpp

@@ -13,9 +13,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-
 #include <stratosphere.hpp>
-#include <stratosphere/spl.hpp>
 
 namespace ams::spl {