Input: amijoy - fix broken table formatting in documentation

Missing '+' led to unintended spanning cell. Correct this.

Signed-off-by: George Anthony Vernon <contact@gvernon.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20250526135957.180254-2-contact@gvernon.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: g-vernon

Documentation/input/devices/amijoy.rst

@@ -123,7 +123,7 @@ JOY1DAT   Y7  Y6  Y5  Y4  Y3  Y2  Y1  Y0     X7  X6  X5  X4  X3  X2  X1  X0
         clocked by 2 of the signals input from the mouse serial
         stream. Starting with first bit received:
 
-         +-------------------+-----------------------------------------+
+         +--------+----------+-----------------------------------------+
          | Serial | Bit Name | Description                             |
          +========+==========+=========================================+
          |   0    | M0H      | JOY0DAT Horizontal Clock                |