dt-bindings: soc: qcom: Add dt-bindings for FSA4480 I2C device

This is a snapshot of driver support for FSA4480 I2C device as of
msm-4.14 commit '96e81628'(Add
driver for FSA4480 I2C device).

Change-Id: I0afb4d49b4b514dda5a95a1f9b171eadc2975a0e
Signed-off-by: Meng Wang <mengw@codeaurora.org>