ARM: dts: msm: Change node for memory hole for 8092

The memory map for mpq8092 has a region of memory that does not
belong to Linux. Add that information into the device tree.

Change-Id: Ia4de7850248810eeb6b61468eb9aa90881035461
Signed-off-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org>