uboot-imx

MLK-20886-3 i2c: Add virtual i2c and virtual i2c mux drivers

Add virtual i2c driver which replies on the VService to send SRTM i2c
messages with M4.
For each output on i2c mux, M4 side abstracts a i2c bus with special bus
id. The virtual i2c mux follows basic mux design, but uses dedicated flag
to pass the abstract bus id for the mux output to virtual i2c driver.

Virtual i2c and virtual i2c mux will bind nodes with compatible string
"fsl,imx-virt-i2c" and "fsl,imx-virt-i2c-mux".

To support binding local i2c driver or virtual i2c driver at runtime. We
provides a override function for the driver bind. ARCH level is responsible
to implement it.

Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit 25095e9f0d9816c22da97945b66439dfa277aa2b)