Remove power button long-press

So far, counting power button's pressing duration is supported.
There's no need to handle redundant case for button long-press.

Tested:
Press buttons and check corresponding behaviors.

Change-Id: I96d9160a10de6d4572148c55e2b7c2a9221d42e2
Signed-off-by: DelphineCCChiu <Delphine_CC_Chiu@wiwynn.com>
diff --git a/src/power_button.cpp b/src/power_button.cpp
index 195030a..80334a8 100644
--- a/src/power_button.cpp
+++ b/src/power_button.cpp
@@ -77,18 +77,9 @@
             "POWER_BUTTON: released");
 
         auto now = std::chrono::steady_clock::now();
-        auto d = std::chrono::duration_cast<std::chrono::milliseconds>(
+        auto d = std::chrono::duration_cast<std::chrono::microseconds>(
             now - getPressTime());
-
-        if (d > std::chrono::milliseconds(LONG_PRESS_TIME_MS))
-        {
-            pressedLong();
-        }
-        else
-        {
-            // released
-            released(std::chrono::duration_cast<std::chrono::microseconds>(d)
-                         .count());
-        }
+        // released
+        released(d.count());
     }
 }