sysfs_driver: add open_path() constructor
sysfs_driver: add lua binding specific methods for accessing 'struct sysfs_driver' members

Note:

currently the 'struct sysfs_driver' is defined like this:
---------------------------------------------------------
struct sysfs_driver {
        char name[SYSFS_NAME_LEN];
        char path[SYSFS_PATH_MAX];
        struct dlist *attrlist;
        char bus[SYSFS_NAME_LEN];

        /* Private: for internal use only */
        struct sysfs_module *module;
        struct dlist *devices;
};
---------------------------------------------------------

For now we provide 'get_name()' and 'get_path()' methods to access
the respective struct member.
sysfs_driver: add get_devices() iterator
sysfs_bus: rename iterator for_each_device() to get_devices()
sysfs_class: rename iterator method for_each_device to get_class_devices
re-generate pregenrated bindings
sysfs_driver: fix to use 'simple ptr' userdata type
re-generate pre-generated bindings