docs(maintainers): add code owners for context management module

This patch adds code owners responsible for maintaining context
management source files in TF-A.

Change-Id: Idc679a907b8380e81d5fbb129fcb74cea5983c0e
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
1 file changed