package/bluez5_utils: correct systemd service install

package/bluez5_utils: correct systemd service install

Commit d732fa4 add the BLUEZ5_UTILS_INSTALL_INIT_SYSTEMD rule, however,
it is not correct.  The [Install] section of bluetooth.service is as
follows:

 [Install]
 WantedBy=bluetooth.target
 Alias=dbus-org.bluez.service

hence there are currently two mistakes:
 1) bluetooth.service is wanted by bluetooth.target not multi-user.target
 2) dbus-org.bluez.service is a missing alias to bluetooth.service

This commit fixes both these issues.

Signed-off-by: Martin Bark <martin@barkynet.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>