Update MAINTAINERS

Add myself as maintainer and George Liu as reviewer.
I am actively working on adding power-utils into this repo, and George
Liu worked on adding json config to make this repo to support other PSU
models.

Signed-off-by: Lei YU <mine260309@gmail.com>
Change-Id: If3fdb5efe099197a4462e6ed5761677fa0e6804a
diff --git a/MAINTAINERS b/MAINTAINERS
index a7f4598..7b6b210 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -44,3 +44,5 @@
 
 M:  Matt Spinler <spinler@us.ibm.com> <mspinler[m]!>
 M:  Shawn McCarney <shawnmm@us.ibm.com> <ShawnMcCarney!>
+M:  Lei Yu <mine260309@gmail.com> <LeiYU!>
+R:  George Liu <liuxiwei@inspur.com> <liuxiwei!>