ARM: msm: Concentrate defconfig on DT supported devices

Make msm_defconfig more focused on DT devices, i.e. MSM8660 and
MSM8960. This will encourage us to focus our efforts on the
devicetree-ification of mach-msm, and help us catch build errors
quicker.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>