msm: ipa4: SMMU additional support for APPS

Change return result at the end of ap_cb_probe to return 0
to prevent a failed error message from printing. Remove
smmu_present flag.

Change-Id: I8b296b68341436f1a0dea2cd7ddbe0096ed17fe2
Crs:fixed: 2219398
Signed-off-by: Michael Adisumarta <madisuma@codeaurora.org>