msm: ipa3: Fix IPA driver usage of msm-bus driver structure

IPA driver assumes specific msm-bus driver structure fields offset
that break compilation when these structures changed.
Update IPA driver usage of these structures to be less
coupled with.

Change-Id: I9972e52e1c53d8b9138196e99d8a7f8d81604020
Signed-off-by: Ghanim Fodi <gfodi@codeaurora.org>