msm: smd_tty: add device tree support to smd_tty drivers

SMD TTY is configured using local tables that do not
allow customization on a per-target basis.

Add device tree support to configure SMD TTY devices.

Change-Id: Ie02dd63a0bec8edff77c8cbeeb72ae7331a0c67a
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Stefanescu Cristian <howerkraft@gmail.com>

Conflicts:
	arch/arm/boot/dts/msm8974.dtsi