Driver Core: x86: add nodename for cpuid and msr drivers.

This adds support to the x86 cpuid and msr drivers to report the proper
device name to userspace for their devices.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>