media: MAINTAINERS: Update entry for Intel IPU3 cio2 driver

This patch adds Bingbu as additional maintainer, and both Tian Shu and Jian Xu
as reviewers for IPU3 CIO2 driver.

Signed-off-by: Yong Zhi <yong.zhi@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>