Unify wording in documentation to use 'top-left' instead 'upper-left'

The Qt documentation is using 'upper-left' everywhere except at
QRect(F) detailed description and Qt::CoordinateSystem enum description.
Therefore fix it in those four places to be consistent.

Task-number: QTBUG-59981
Change-Id: Ie652044d0207ea5a42888d9e1f1dc9a86b1e9410
Reviewed-by: Mats Honkamaa <mats.honkamaa@qt.io>
Reviewed-by: Tarja Sundqvist <tarja.sundqvist@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

src/corelib/global/qnamespace.qdoc

@@ -2959,10 +2959,10 @@
 
     This enum specifies the coordinate system.
 
-    \value DeviceCoordinates Coordinates are relative to the upper-left corner
+    \value DeviceCoordinates Coordinates are relative to the top-left corner
     of the object's paint device.
 
-    \value LogicalCoordinates Coordinates are relative to the upper-left corner
+    \value LogicalCoordinates Coordinates are relative to the top-left corner
     of the object.
 */
 

src/corelib/tools/qrect.cpp

@@ -54,7 +54,7 @@ QT_BEGIN_NAMESPACE
     \brief The QRect class defines a rectangle in the plane using
     integer precision.
 
-    A rectangle is normally expressed as an upper-left corner and a
+    A rectangle is normally expressed as a top-left corner and a
     size.  The size (width and height) of a QRect is always equivalent
     to the mathematical rectangle that forms the basis for its
     rendering.
@@ -1317,7 +1317,7 @@ QDebug operator<<(QDebug dbg, const QRect &r)
     \brief The QRectF class defines a rectangle in the plane using floating
     point precision.
 
-    A rectangle is normally expressed as an upper-left corner and a
+    A rectangle is normally expressed as a top-left corner and a
     size.  The size (width and height) of a QRectF is always equivalent
     to the mathematical rectangle that forms the basis for its
     rendering.