ARM: dts: msm: add wlan carveout region for sdm660/sdm630

Add WLAN carveout region of size 1MB. But additional guard of 1MB is
also added due to system limitations.

Change-Id: I1cd38f1ced820132209e31acc55a1321c879a09c
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>