staging: mei: mei_dev - use type bool instead of int

use type bool for boolean variables in struct mei_dev
this should save some space providing boolean is 8 bits

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Oren Weil <oren.jer.weil@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>