configure script assumes embedded platform is not cross-compiled under Cygwin

Hi,

When configure tries to auto-detect the CFG_EMBEDDED setting under Cygwin, it assumes x86:

CYGWIN*:*)
CFG_EMBEDDED=x86
;;

I am cross-compiling to a new platform that is PowerPC based under Cygwin, so this assumption is not correct. I think a block should be added around that like the other systems have: "if [ -z "$XPLATFORM" ]; then".

-Ben