ARM: dts: msm: Reduce size of offline-able memory region

Since offline-able memory is in ZONE_MOVEABLE, it may not be
used for GFP_KERNEL allocations. Experiments have shown that
the previous setting causes the system to run out of memory
for GFP_KERNEL type allocations.

Change-Id: I3d284b324eb10ad1907e5eaf0df27c65acd29a3b
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>