arm/dt: msm8974: Split device tree for CDP and MTP

Add the DTS file for the MSM8974 MTP target, and remove the
MTP device ID from the CDP DTS file, to allow accounting
for hardware differences between the CDP and MTP platforms.

Change-Id: Ie9734a027e46c3a4c621d4252a6149d97c1cf76d
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>