regulators: Convert to new SensorType enumeration

There are several types of voltage regulator sensors, such as vout,
iout, and temperature.

The sensor types were previously defined by the enumeration
pmbus_utils::SensorValueType.  This enumeration should not have been
placed in the pmbus_utils namespace because it is not specific to PMBus.

A new enumeration with the simpler name SensorType was created in
sensors.hpp in a previous commit.

Remove the old enumeration from pmbus_utils.  Convert affected files to
use the new enumeration.

Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
Change-Id: I4136b392b104edd3eee41ec29c779ad084c7c4de
diff --git a/phosphor-regulators/test/rail_tests.cpp b/phosphor-regulators/test/rail_tests.cpp
index 089e6ee..f0d9529 100644
--- a/phosphor-regulators/test/rail_tests.cpp
+++ b/phosphor-regulators/test/rail_tests.cpp
@@ -27,6 +27,7 @@
 #include "rail.hpp"
 #include "rule.hpp"
 #include "sensor_monitoring.hpp"
+#include "sensors.hpp"
 #include "system.hpp"
 
 #include <memory>
@@ -271,7 +272,7 @@
         EXPECT_CALL(journal, logError(A<const std::string&>())).Times(0);
 
         // Create PMBusReadSensorAction
-        pmbus_utils::SensorValueType type{pmbus_utils::SensorValueType::iout};
+        SensorType type{SensorType::iout};
         uint8_t command = 0x8C;
         pmbus_utils::SensorDataFormat format{
             pmbus_utils::SensorDataFormat::linear_11};