change chan osc range - PLEASE READ

as of now the range is ~32768, either from -16384 to 16383, or 0 to 32767.
it previously was -32768 to 32767 (~65536).

this change was made to better suit chips that only output a positive value.
if you are working on a new chip, update your code and shift right by one if necessary.

src/engine/platform/namcowsg.cpp

@@ -177,7 +177,7 @@ void DivPlatformNamcoWSG::acquire(short** buf, size_t len) {
     };
     namco->sound_stream_update(bufC,1);
     for (int i=0; i<chans; i++) {
-      oscBuf[i]->data[oscBuf[i]->needle++]=namco->m_channel_list[i].last_out*chans;
+      oscBuf[i]->data[oscBuf[i]->needle++]=(namco->m_channel_list[i].last_out*chans)>>1;
     }
   }
 }