watchdog: utilize new default_interval parameter

Commit fb9869ff introduced the concept of passing in a default interval
timeout to the watchdog application on startup. This utilized the
existing --min_interval option. This worked ok but it limited the
ability of external users to reduce the interval.

Give the above limitation, a new feature was added to phosphor-watchdog
which allows the user to explicitly set the default interval on startup
in the following commit:
 https://github.com/openbmc/phosphor-watchdog/commit/afc369ad548137a5fdb0bc69b6606e2aafa7182b

Utilize this new parameter to set the default interval on startup.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Ia21dc7bb9dec50f3ec044c6d1733a54bcea15298
diff --git a/meta-phosphor/recipes-phosphor/watchdog/phosphor-watchdog/phosphor-watchdog@.service b/meta-phosphor/recipes-phosphor/watchdog/phosphor-watchdog/phosphor-watchdog@.service
index 1f65902..e559d9f 100644
--- a/meta-phosphor/recipes-phosphor/watchdog/phosphor-watchdog/phosphor-watchdog@.service
+++ b/meta-phosphor/recipes-phosphor/watchdog/phosphor-watchdog/phosphor-watchdog@.service
@@ -4,4 +4,4 @@
 [Service]
 Restart=no
 EnvironmentFile={envfiledir}/obmc/watchdog/%I
-ExecStart=/usr/bin/phosphor-watchdog --continue --service=${{SERVICE}} --path=${{DEVPATH}} --target=${{TARGET}} --min_interval=${{TIMEOUT_IN_MSEC}}
+ExecStart=/usr/bin/phosphor-watchdog --continue --service=${{SERVICE}} --path=${{DEVPATH}} --target=${{TARGET}} --default_interval=${{TIMEOUT_IN_MSEC}}