AML: Send h263 to software decoding sooner

* AMLCodec was handling it prior
https://github.com/xbmc/xbmc/blob/master/xbmc/cores/dvdplayer/DVDCodecs/Video/AMLCodec.cpp#L1225

Signed-off-by: Brandon McAnsh <brandonm@matricom.net>
Can't see where, but yes, if it exists. 
Leave the "default:" one, though.