[calls] metainfo: Add "requires" tag in favour of custom tags

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit f42d06071558e79acbef433925265d2da3d13fda
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Tue Oct 19 19:26:47 2021 +0200

    metainfo: Add "requires" tag in favour of custom tags
    
    As described in
    https://blogs.gnome.org/tbernard/2021/09/07/ready-for-software-41/

 data/org.gnome.Calls.metainfo.xml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/data/org.gnome.Calls.metainfo.xml b/data/org.gnome.Calls.metainfo.xml
index 309c7535..5cf4089c 100644
--- a/data/org.gnome.Calls.metainfo.xml
+++ b/data/org.gnome.Calls.metainfo.xml
@@ -28,6 +28,10 @@
       </screenshot>
     </screenshots>
 
+    <requires>
+      <display_length compare="ge">360</display_length>
+    </requires>
+
     <recommends>
         <control>pointing</control>
         <control>keyboard</control>
@@ -67,8 +71,4 @@
       </release>
     </releases>
 
-    <custom>
-        <value key="Purism::form_factor">workstation</value>
-        <value key="Purism::form_factor">mobile</value>
-    </custom>
 </component>