mei: implement mei_cl_connect function

Implement mei_cl_connect that warps host client
parts of the connection and leave the ioctl specifics
in the mei_ioctl_connect_client function.
Move mei_ioctl_connect_client to main.c where it
belongs

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