Doc: don't use the term SDK in connection with Qt

Replace with "Qt distributions" or "installers" or rewrite
in some other way.

Remove references to installing Qt 4 SDK, because it is
no longer available for downloading.

Change-Id: I291f82702e21d953f2efbb0e634d6454b4bc17b9
Reviewed-by: hjk <hjk121@nokiamail.com>

doc/src/overview/creator-mobile-targets.qdoc

@@ -31,10 +31,9 @@
     \title Connecting Mobile Devices
 
     You can connect mobile devices to the development PC to build, run, debug,
-    and analyze applications on them from \QC. When you install an SDK for a
+    and analyze applications on them from \QC. When you install Qt for a
     target platform, such as Android or QNX, the build and run settings for the
-    development targets delivered with the SDK might be set up automatically in
-    \QC.
+    development targets might be set up automatically in \QC.
 
     You can connect the device to the development PC using a USB connection.
     Additionally, you can connect Linux-based devices by using a WLAN
@@ -45,12 +44,12 @@
         \li \l{Connecting Android Devices}
 
             Qt applications for Android are compiled as \c {shared objects} that
-            are loaded by a Java launcher generated by the Qt for Android SDK.
+            are loaded by a Java launcher that is part of Qt.
             This is totally transparent to users. As Qt is composed of libraries
             referencing each other, Qt 4 applications are only supported on
             Android version 1.6, or later, and Qt 5 applications on version
-            2.3.3, or later. You must install the Qt for Android SDK to develop
-            for Android devices.
+            2.3.3, or later. You must install a Qt version targeting Android and
+            the Android SDK and NDK to develop for Android devices.
 
         \li \l{Connecting Bare Metal Devices}