x86, defconfig: Add DEVTMPFS and DEVTMPFS_MOUNT to *86*_defconfig

The defconfig kernel can not run under neither fedora16 x86_64 laptop
nor fedora17 x86_64 pc. After enable DEVTMPFS* in x86_64_defconfig, it
will be OK.

DEVTMPFS* is only related with software, so for i386_defconfig may also
need them (at least, it has no negative effect for defconfig).

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Link: http://lkml.kernel.org/r/52784DFF.8040004@asianux.com


Signed-off-by: H. Peter Anvin <hpa@zytor.com>