ARM: msm: Specify dtbs for DT targets

Specify the dtb files for the devicetree targets so that 'make dtbs'
will generate these files during the build.

Change-Id: Ic3e3aa13b10815a00ef020a2900b649a90f78d1e
Signed-off-by: David Brown <davidb@codeaurora.org>
[sboyd: Also drop upstream dtb files so that android doesn't pick
them up]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>