README.md: remove deviceinfo_parse (MR 2469)

The command has been removed, so remove it from README.md too.

README.md

@@ -254,11 +254,6 @@ Use `-v` on any action to get verbose logging:
 $ pmbootstrap -v build hello-world
 ```
 
-Parse a single deviceinfo and return it as JSON:
-```
-$ pmbootstrap deviceinfo_parse pine64-pinephone
-```
-
 Parse a single APKBUILD and return it as JSON:
 ```
 $ pmbootstrap apkbuild_parse hello-world