sdk: Do not create link in /opt/sysroot

Use the mount unit to bind mount the directory instead.
This is because of a bug in gdb parsing symbolic links.
See T4391

Signed-off-by: Frédéric Dalleau <frederic.dalleau@collabora.com>

Differential Revision: https://phabricator.apertis.org/D7433

scripts/setup_sysroot.chroot

@@ -2,8 +2,6 @@
 
 set -e
 
-echo "I: create sysroot directory"
+echo "I: create sysroot directory on home partition"
 install -d -m 0755 /home/sysroot
 chown user.user /home/sysroot
-echo "I: link /opt/sysroot to sysroot directory"
-ln -sf ../home/sysroot /opt/sysroot