powerstats: Simplify Power Stats HAL API

Removing unused types, and statuses.

Removing getPowerEntityStateSpace and moving that functionality into
getPowerEntityInfo.

Bug: 167218032
Test: m
Change-Id: I6dabd18a41338e715713f43c2e009003dcc003b6
diff --git a/powerstats/aidl/default/PowerStats.cpp b/powerstats/aidl/default/PowerStats.cpp
index 50a829e..8d6a0ee 100644
--- a/powerstats/aidl/default/PowerStats.cpp
+++ b/powerstats/aidl/default/PowerStats.cpp
@@ -34,13 +34,7 @@
     (void)_aidl_return;
     return ndk::ScopedAStatus::ok();
 }
-ndk::ScopedAStatus PowerStats::getPowerEntityStateInfo(
-        const std::vector<int32_t>& in_powerEntityIds,
-        std::vector<PowerEntityStateSpace>* _aidl_return) {
-    (void)in_powerEntityIds;
-    (void)_aidl_return;
-    return ndk::ScopedAStatus::ok();
-}
+
 ndk::ScopedAStatus PowerStats::getPowerEntityStateResidencyData(
         const std::vector<int32_t>& in_powerEntityIds,
         std::vector<PowerEntityStateResidencyResult>* _aidl_return) {
@@ -48,6 +42,7 @@
     (void)_aidl_return;
     return ndk::ScopedAStatus::ok();
 }
+
 ndk::ScopedAStatus PowerStats::getRailInfo(std::vector<RailInfo>* _aidl_return) {
     (void)_aidl_return;
     return ndk::ScopedAStatus::ok();