RFC: small syscons and kbd patch

Dear Hackers,

can someone please review the attached small patch for syscons and
kbd? it should be a no-op mostly. the patch basically does

1) removes bogus layering in syscons, i.e. basically removes sccngetch();
2) implements advisory lock for kbd (based on atomic(9));
3) implements new POLLED flag for kbd;

this is a part of a plan to fix keyboard access races in syscons.

thanks,
max