msm: ipa3: Fix to unmap LOW LAT consumer pipe buffers

Currently LOW LAT consumer pipe replnish skb not unmapped
properly. Due to this running into out of memory issue.
Adding changes to unmap LOW LAT consumer replnish buffers
using correct method.

Change-Id: I253519f7c2f5eba11d32074c7b1879feed1f413c
Signed-off-by: Ashok Vuyyuru <avuyyuru@codeaurora.org>