build: Update kconfig to version in Linux 3.13.

Update kconfig (from Linux v3.11-rc6) to the latest version (Linux
v3.13).

This copyies 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>
11 files changed