msm-auto: defconfig: Enable USB_QCOM_IPC_BRIDGE config

Enable USB_QCOM_IPC_BRIDGE config which is required to compile
HSIC transport IPC router driver. Also update the Kconfig
dependency chain and documentation to make the user select this
config manually.

Change-Id: I85f61aac136504a96c2e4ce94907355d23413e42
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>