Change notification-service resource type

Change notification-service resource type

It is required to change notification-service resource type to pass CTT as below.
x.org. naming scheme is accepted as vendor specific resource name
during OCF F2F meeting in Vegas.

oic.wk.xxx -> x.org.iotivity.xxx

Change-Id: I7e9d50c315ad7cd4beda6b4454e525dc03d3bfb5
Signed-off-by: cc <ch79.cho@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/16687
Reviewed-by: Uze Choi <uzchoi@samsung.com>
Tested-by: Uze Choi <uzchoi@samsung.com>