msm: ipa: wan driver fix excp_pipe enum

transport driver adds support to define excp_pipe
enum when register rmnet_data0 to rmnet_data7
interface property to IPA hardware

Change-Id: I71628e76fa8d00dc2429353d6944407de4ab7ffc
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>