Fix typos

Change-Id: I333a33a65ce4ff2469f7eb66663808cb75d756a2
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

src/effects/DirectionalBlur.qml

@@ -85,7 +85,7 @@ Item {
     property variant source
 
     /*!
-        This property defines the percieved amount of movement for each pixel.
+        This property defines the perceived amount of movement for each pixel.
         The movement is divided evenly to both sides of each pixel.
 
         The quality of the blur depends on \l{DirectionalBlur::samples}{samples}

src/effects/DropShadow.qml

@@ -104,7 +104,7 @@ Item {
         Radius defines the softness of the shadow. A larger radius causes the
         edges of the shadow to appear more blurry.
 
-        The ideal blur is acheived by selecting \c samples and \c radius such
+        The ideal blur is achieved by selecting \c samples and \c radius such
         that \c {samples = 1 + radius * 2}, such as:
 
         \table

src/effects/GaussianBlur.qml

@@ -92,7 +92,7 @@ Item {
         affect the blurring of an individual pixel. A larger radius increases
         the blur effect.
 
-        The ideal blur is acheived by selecting \c samples and \c radius such
+        The ideal blur is achieved by selecting \c samples and \c radius such
         that \c {samples = 1 + radius * 2}, such as:
 
         \table

src/effects/Glow.qml

@@ -105,7 +105,7 @@ Item {
         Depending on the radius value, value of the \l{Glow::samples}{samples}
         should be set to sufficiently large to ensure the visual quality.
 
-        The ideal blur is acheived by selecting \c samples and \c radius such
+        The ideal blur is achieved by selecting \c samples and \c radius such
         that \c {samples = 1 + radius * 2}, such as:
 
         \table