ads7846: fix endianness on coordinate values

Remove conversion from Big Endian to CPU order in the ads7846 driver.
We expect the uWire SPI driver to do this for us. Also the shift on read
values should be only 3, since we have a dummy clock at the beginning.
Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: Juha Yrjölä <juha.yrjola@nokia.com>

drivers/input/touchscreen/ads7846.c

@@ -257,10 +257,10 @@ static void ads7846_rx(void *ads)
 	/* adjust:  12 bit samples (left aligned), built from
 	 * two 8 bit values writen msb-first.
 	 */
-	x = be16_to_cpu(ts->tc.x) >> 4;
-	y = be16_to_cpu(ts->tc.y) >> 4;
-	z1 = be16_to_cpu(ts->tc.z1) >> 4;
-	z2 = be16_to_cpu(ts->tc.z2) >> 4;
+	x = ts->tc.x >> 3;
+	y = ts->tc.y >> 3;
+	z1 = ts->tc.z1 >> 3;
+	z2 = ts->tc.z2 >> 3;
 
 	/* range filtering */
 	if (x == MAX_12BIT)