manifest: update libmodem revision

Update libmodem revision.

Signed-off-by: Andreas Moltumyr <[email protected]>

Author: anhmolt

west.yml

@@ -218,7 +218,7 @@ manifest:
           upstream-sha: 1be6ca7253133a21a1e9fe0fbb4656e17d63a936
           compare-by-default: false
     - name: libmodem
-      revision: 5f5837a5a0c9e2082e76b1e921152532f9f486f2
+      revision: 5dc5bc768dda0ddf9974920c618b70da5d67c6c3
       groups:
         - libmodem
     - name: openthread