Input: elantech - ignore high bits in the position coordinates

In older versions of the elantech hardware/firmware those bits always
were unset, so it didn't actually matter, but newer versions seem to
use those high bits for something else, screwing up the coordinates
we report to the input layer for those devices.

Signed-off-by: Florian Ragwitz <rafl@debian.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt
index a10c3b6..56941ae 100644
--- a/Documentation/input/elantech.txt
+++ b/Documentation/input/elantech.txt
@@ -333,14 +333,14 @@
 byte 1:
 
    bit   7   6   5   4   3   2   1   0
-        x15 x14 x13 x12 x11 x10 x9  x8
+         .   .   .   .   .  x10 x9  x8
 
 byte 2:
 
    bit   7   6   5   4   3   2   1   0
         x7  x6  x5  x4  x4  x2  x1  x0
 
-         x15..x0 = absolute x value (horizontal)
+         x10..x0 = absolute x value (horizontal)
 
 byte 3:
 
@@ -350,14 +350,14 @@
 byte 4:
 
    bit   7   6   5   4   3   2   1   0
-        y15 y14 y13 y12 y11 y10 y8  y8
+         .   .   .   .   .   .  y9  y8
 
 byte 5:
 
    bit   7   6   5   4   3   2   1   0
         y7  y6  y5  y4  y3  y2  y1  y0
 
-         y15..y0 = absolute y value (vertical)
+         y9..y0 = absolute y value (vertical)
 
 
 4.2.2 Two finger touch