codeowners: update due to Github user name change

Update CODEOWNERS and MAINTAINERS due to Github user name change.

Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>
diff --git a/MAINTAINERS.yml b/MAINTAINERS.yml
index ac5e42c..e454d33 100644
--- a/MAINTAINERS.yml
+++ b/MAINTAINERS.yml
@@ -282,7 +282,7 @@
     maintainers:
         - vanwinkeljan
     collaborators:
-        - jfischer-phytec-iot
+        - jfischer-no
     files:
         - drivers/display/
         - dts/bindings/display/
@@ -1056,7 +1056,7 @@
         - erwango
     collaborators:
         - avisconti
-        - jfischer-phytec-iot
+        - jfischer-no
     files:
         - boards/shields/
     labels:
@@ -1131,7 +1131,7 @@
     # Provisional entry, subject to approval
     status: maintained
     maintainers:
-        - jfischer-phytec-iot
+        - jfischer-no
     collaborators:
         - finikorg
     files: