media: v4l: Fix references in Intel IPU3 Bayer documentation

The references in Intel IPU3 Bayer format documentation were wrong. Fix
them.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/media/uapi/v4l/pixfmt-srggb10-ipu3.rst

 .. -*- coding: utf-8; mode: rst -*-
 
-.. _V4L2_PIX_FMT_IPU3_SBGGR10:
-.. _V4L2_PIX_FMT_IPU3_SGBRG10:
-.. _V4L2_PIX_FMT_IPU3_SGRBG10:
-.. _V4L2_PIX_FMT_IPU3_SRGGB10:
+.. _v4l2-pix-fmt-ipu3-sbggr10:
+.. _v4l2-pix-fmt-ipu3-sgbrg10:
+.. _v4l2-pix-fmt-ipu3-sgrbg10:
+.. _v4l2-pix-fmt-ipu3-srggb10:
 
 **********************************************************************************************************************************************
 V4L2_PIX_FMT_IPU3_SBGGR10 ('ip3b'), V4L2_PIX_FMT_IPU3_SGBRG10 ('ip3g'), V4L2_PIX_FMT_IPU3_SGRBG10 ('ip3G'), V4L2_PIX_FMT_IPU3_SRGGB10 ('ip3r')