fans: Update service start limits for fan watchdog

It was found that the fan control services were constantly getting
restarted due to not failing within the previous start limits. After
experimenting with different combinations of limits, using the default
values for StartLimitBurst and StartLimitIntervalSec is sufficient.

Tested:
    Changed limits, powered on, watched service fails in journal until
fan watchdog monitor started

Resolves: openbmc/phosphor-fan-presence#23

Change-Id: I137807dd8c2e09e3a4019a9ad416b0384824ed65
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>

recipes-phosphor/fans/phosphor-fan/fan-watchdog-monitor.conf

@@ -1,5 +1,3 @@
 [Unit]
 #These overrides allow the fan watchdog to take over when this service dies
 OnFailure=fan-watchdog-monitor@%n.service
-StartLimitIntervalSec=5
-StartLimitBurst=3