main/swclock-offset: move to its own repository (MR 3642)

To make "swclock-offset" available to other projects as well, it was
moved to its own repository.

.ci/shellcheck.sh

@@ -24,8 +24,6 @@ sh_files="
 	./main/postmarketos-mkinitfs-hook-debug-shell/20-debug-shell.sh
 	./main/postmarketos-mkinitfs-hook-netboot/netboot.sh
 	./main/postmarketos-update-kernel/update-kernel.sh
-	./main/swclock-offset/swclock-offset-boot.sh
-	./main/swclock-offset/swclock-offset-shutdown.sh
 	./main/ttyescape/*.post-install
 	./main/unl0kr/unlock.sh
 	./main/msm-firmware-loader/*.post-install