i2c-mux: pca954x: support pca9646 i2c switch

Add the PCA9646 support, which is 2-wire bus switch and buffered 4-channel.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
1 file changed