mei: use local cl variables in wd and amthif

Use local cl variable instead of dev->iamthif_cl and dev->wd_cl
as the first step to use dynamic allocation of these clients
as their are not supported on all platforms

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>