update tvservice.md (#1545)

Yemtex · web-flow · commit 0a78c85fd428 · 2020-05-14T13:53:23.000+01:00
updated -m
there is no CVT group
changed it to CEA
diff --git a/raspbian/applications/tvservice.md b/raspbian/applications/tvservice.md
@@ -36,7 +36,7 @@ Power on the SDTV (composite output) with the specified mode, `PAL` or `NSTC`, a
 
 #### -m, --modes=Group
 
-where Group is `CVT` or `DMT`.
+where Group is `CEA` or `DMT`.
 
 Shows a list of display modes available in the specified group.
 
