build: Update kconfig to version in Linux 3.16.

Update kconfig (from Linux v3.13) to the latest version (Linux v3.16).

This copies kconfig from Linux with only the changes necessary to work
with the SeaBIOS build (the equivalent of the earlier SeaBIOS 0da7bfdf
commit) and the changes necessary to always emit symbols (SeaBIOS
b623e7c5 commit).

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
22 files changed