x86: remove all now-duplicate header files

All files that have been made identical to the asm-generic
version in the previous patches can now be removed,
guaranteeing that this does not introduce semantic changes.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
LKML-Reference: <cover.1245354003.git.arnd@arndb.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>