msm: ipa3: Fix to save the ntn buffers in SMMU disabled case

Not able to unmap the buffers due not saving data buffers
when SMMU disabled on EMAC side. Adding changes to save the
data buffer list in EMAC SMMU disabled case also.

Change-Id: Ia22110b450477927c35942f2161c2730086da892
Signed-off-by: Ashok Vuyyuru <avuyyuru@codeaurora.org>