Move memset6() declaration to string-extra.h, kills a warning compiling for android since it ships a memory.h.

2010-08-12T13:55:01+00:00

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27789 a1c6a512-1295-4272-9138-f99709370657

rockbox/firmware/include/memset16.h, branch quake5