Add __sh__ cpu arch support

This Patch adds the __sh__ cpu arch to xbmc (--host=sh4-linux).

Note: Even with this patch you wont be able to compile a runnable version of xbmc for sh4, as for that you will need the OpenGL ESv1 patch which I am currently still trying to merge in a clean way with xbmc.

And of course the patch to access the video and audio hardware decoder by using gstreamer and bypassing paplayer and dvdplayer is also still in merging process.