media: uapi book: Fix a few Sphinx warnings

Solve the following issues:

	Documentation/media/uapi/v4l/dev-sliced-vbi.rst:208: ERROR: Content block expected for the "raw" directive; none found.
	Documentation/media/uapi/v4l/dev-sliced-vbi.rst:216: ERROR: Content block expected for the "raw" directive; none found.
	Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst:645: ERROR: Content block expected for the "raw" directive; none found.

Fixes: 70b074df4ed1 ("media: fix pdf build with Spinx 1.6")
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/uapi/v4l/dev-sliced-vbi.rst

@@ -206,6 +206,7 @@ struct v4l2_sliced_vbi_format
 	Applications and drivers must set it to zero.
 
 .. raw:: latex
+
     \endgroup
 
 .. _vbi-services2:
@@ -214,6 +215,7 @@ Sliced VBI services
 -------------------
 
 .. raw:: latex
+
     \footnotesize
 
 .. tabularcolumns:: |p{4.1cm}|p{1.1cm}|p{2.4cm}|p{2.0cm}|p{7.3cm}|

Documentation/media/uapi/v4l/pixfmt-packed-rgb.rst

@@ -642,8 +642,6 @@ The meaning of their alpha bits ``(a)`` are ill-defined and interpreted as in
 either the corresponding ARGB or XRGB format, depending on the driver.
 
 
-.. raw:: latex
-
 .. raw:: latex
 
     \begingroup