Revert "ARM: dts: msm: remove qcom,guard-memory property for rmtfs"

This reverts commit 670bf7c2.
XPU h/w issue is still present on sm8150 v1/v2 target.
so enabling this WA for sm8150.

Change-Id: Iec6a79384289e8d5f048d7b21efdc80759a239ce
Signed-off-by: Ankit Jain <jankit@codeaurora.org>