include: rmnet_data: Add snapshot of headers

While rmnet_data driver itself is not required, some of the
definitions are used by modules such as mhi and ipa.

Change-Id: I892c2ff51819262632769b3da32a1c2adf6b3543
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>