[media] docs-rst: v4l2-drivers book: adjust column margins

A few tables are not properly output on LaTeX format.

Fix them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/Documentation/media/v4l-drivers/cpia2.rst b/Documentation/media/v4l-drivers/cpia2.rst
index 763705c..b512501 100644
--- a/Documentation/media/v4l-drivers/cpia2.rst
+++ b/Documentation/media/v4l-drivers/cpia2.rst
@@ -55,6 +55,9 @@
 Driver options
 ~~~~~~~~~~~~~~
 
+.. tabularcolumns:: |p{13ex}|L|
+
+
 ==============  ========================================================
 Option		Description
 ==============  ========================================================