msm: ipa: Fix to decouple MHI initialization from uC load

MHI initializtion doesn't need to wait till uC is loaded as it
is independent. Make a change to decouple.

Change-Id: I63cc9887d6e69416d933ee17097e0c7d0ee707c9
Signed-off-by: Chaitanya Pratapa <cpratapa@codeaurora.org>