services: Consistently use SDDM rather than GDM on non-x86_64.

This is a follow-up to 49599fab564f203b8e92d32e9b28c99e99849bfb.

Fixes: <https://issues.guix.gnu.org/52908>.

* gnu/services/xorg.scm (set-xorg-configuration)[login-manager-service-type]:
When the current system or target system begins with the string "x86_64", use
gdm-service-type as before; otherwise, use sddm-service-type.
* gnu/system/examples/vm-image.tmpl (services): Add sddm-service-type to the
list of service types to remove.

1 files changed, 3 insertions, 3 deletions

diff --git a/gnu/system/examples/vm-image.tmpl b/gnu/system/examples/vm-image.tmpl
index a59d91587b..ccb0b045db 100644
--- a/gnu/system/examples/vm-image.tmpl
+++ b/gnu/system/examples/vm-image.tmpl
@@ -5,7 +5,7 @@
 ;;
 
 (use-modules (gnu) (guix) (srfi srfi-1))
-(use-service-modules desktop mcron networking spice ssh xorg)
+(use-service-modules desktop mcron networking spice ssh xorg sddm)
 (use-package-modules bootloaders certs fonts nvi
                      package-management wget xorg)
 
@@ -107,12 +107,12 @@ root ALL=(ALL) ALL
                  ;; Use the DHCP client service rather than NetworkManager.
                  (service dhcp-client-service-type))
 
-           ;; Remove GDM, ModemManager, NetworkManager, and wpa-supplicant,
-           ;; which don't make sense in a VM.
+           ;; Remove some services that don't make sense in a VM.
            (remove (lambda (service)
                      (let ((type (service-kind service)))
                        (or (memq type
                                  (list gdm-service-type
+                                       sddm-service-type
                                        wpa-supplicant-service-type
                                        cups-pk-helper-service-type
                                        network-manager-service-type