ARM: dts: msm: remove undefined property usage in msm8996

Splash memory node is trying to reserve the memory
using device tree properties which are not supported.
This change cleans up thos unused properties.

Change-Id: I698067d3f9c9210e2f7f968e92b6487c9c278e0d
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>