Fix various spelling mistakes and typos

Change-Id: Ie4ff17b5abdc1ac4c7c378ead91ee9065e4fd32f
diff --git a/src/devices/input/overview.jd b/src/devices/input/overview.jd
index 11cdf97..44091cf 100644
--- a/src/devices/input/overview.jd
+++ b/src/devices/input/overview.jd
@@ -181,7 +181,7 @@
 using constants that begin with the prefix <code>SW_</code>.  The Linux
 kernel input drivers report switch state changes as <code>EV_SW</code> events.</p>
 <p>Android applications generally do not receive events from switches,
-but the system may use them interally to control various
+but the system may use them internally to control various
 device-specific functions.</p>
 </dd>
 <dt>Android Key Code</dt>