i2c: virtio: update the maintainer to Conghui

Due to changes in my work, I'm passing the virtio-i2c driver
maintenance to Conghui.

Signed-off-by: Jie Deng <jie.deng@intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>