Device tree support is added for Qualcomm I2C controller and documentation is provided for required and optional device-node properties. Slave devices can be added using register_board_info (boards file), or by listing them as child of I2C of_node in the device tree. Change-Id: I10e9b8c7805c49dfe6a51975129f1599bbca84eb Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>