Add vishwa as Maintainer

I have implemented the first version of phosphor-watchdog
and have started to follow the changes in gerrit / mailing list

Change-Id: Iac9a135bf1447e62d3513c2be82139c78ca0d4f4
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
1 file changed