conf change: rename zone variables

Rename the zone variables to make them camelCase as a step towards
making all configuration variables camelCase for consistency.

Note: This patchset requires a change to your yaml configuration if
you're using it, or libconfig if you're using it.

Change-Id: If9cf1d7eb8227d305a1625275f2f7082c0d6905a
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/examples/swampd.conf b/examples/swampd.conf
index c17a75c..c4fab5e 100644
--- a/examples/swampd.conf
+++ b/examples/swampd.conf
@@ -58,7 +58,7 @@
 
 zones = (
   { id = 0x01
-    minthermalrpm = 3000.0
+    minThermalRpm = 3000.0
     failsafepwm = 90.0
     pids = (
       { name = "allfans"