ARM: dts: qcom: Add initial IFC6540 board device tree

Add basic support for the IFC6540 single-board computer boards, that are
based on the APQ8084 SoC. This patch adds the initial device tree and the
neccessary nodes required for enabling the serial port and eMMC.

Signed-off-by: Georgi Djakov <gdjakov@mm-sol.com>
Signed-off-by: Kumar Gala <galak@codeaurora.org>