ARM: dts: msm: Change memory hole for 8916

The memory hole code is now different for arm64 vs. arm.
Switch to a different method of specifying the memory hole which
is compatible with both arm and arm64.

Change-Id: I7cf725e9cb9e4a10ffa715b14a7d92a47b309f74
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>