driver core: Convert some drivers to CLASS_ATTR_STRING

Convert some drivers who export a single string as class attribute
to the new class_attr_string functions. This removes redundant
code all over.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

6 files changed