openpower-debug-collector: Define checkstop and watchdog services

openpower-debug-collector had the checkstop service which was
getting invoked in host checkstop scenario. Now there is a need
to get debug data in case of host watchdog timeout scenarios and
this commit adds that support.

Fixes openbmc/openbmc#1634

Change-Id: Iadb7ba516cbdd2d8010c66912bdcd647800aa198
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
3 files changed