ARM: dts: msm: move cnss related nodes to board device tree for sa6155

The configurations for external BT/WLAN devices are
NOT SoC specific, but board specific.
Therefore, move them from SoC device tree to board
device tree.

Change-Id: Ifd7be297d6477e5d94564106218c41e0b2fae726
Signed-off-by: Yu Wang <yyuwang@codeaurora.org>