mxf: Update mpeg video caps

We now properly detect profile/level for these streams

medias/defaults/mxf/op1a-pal-mpeg2.mxf.media_info

 <file duration="1720000000" frame-detection="1" uri="file:///home/thiagoss/gst-validate/gst-integration-testsuites/medias/defaults/mxf/op1a-pal-mpeg2.mxf" seekable="true">
-  <streams caps="application/mxf">    <stream type="video" caps="video/mpeg, mpegversion=(int)2, systemstream=(boolean)false, framerate=(fraction)25/1, interlaced=(boolean)true, width=(int)720, height=(int)608, pixel-aspect-ratio=(fraction)152/135, parsed=(boolean)true, codec_data=(buffer)000001b32d026023493e23d8000001b5185400010080000001b200010100070200, interlace-mode=(string)mixed" id="2041126dc4134567114ff7b038f737a6f47f51426811d0327dfc03d3005add93/002">
+  <streams caps="application/mxf">    <stream type="video" caps="video/mpeg, mpegversion=(int)2, systemstream=(boolean)false, framerate=(fraction)25/1, interlaced=(boolean)true, width=(int)720, height=(int)608, pixel-aspect-ratio=(fraction)152/135, parsed=(boolean)true, codec_data=(buffer)000001b32d026023493e23d8000001b5185400010080000001b200010100070200, profile=(string)4:2:2, level=(string)main, interlace-mode=(string)mixed" id="2041126dc4134567114ff7b038f737a6f47f51426811d0327dfc03d3005add93/002">
        <frame duration="40000000" id="0" is-keyframe="true" offset="0" offset-end="18446744073709551615" pts="0"  dts="0" running-time="0" checksum="d319775e2432d4ee1e98906169e7105b"/>
        <frame duration="40000000" id="1" is-keyframe="true" offset="150000" offset-end="18446744073709551615" pts="40000000"  dts="40000000" running-time="40000000" checksum="04244c7c37d94215cf80a17db80df4d0"/>
        <frame duration="40000000" id="2" is-keyframe="true" offset="300000" offset-end="18446744073709551615" pts="80000000"  dts="80000000" running-time="80000000" checksum="f64b31b0bb9a27c94dd109383b7cc432"/>