move service files from Yocto layer

This change relocates phosphor-led-manager service files from the Yocto
layer to the phosphor-led-manager repository.
It also ensures that non-user executables ar

move service files from Yocto layer

This change relocates phosphor-led-manager service files from the Yocto
layer to the phosphor-led-manager repository.
It also ensures that non-user executables are installed in the libexec.

[1]: https://github.com/openbmc/docs/blob/master/anti-patterns.md#incorrect-placement-of-executables-in-sbin-usrsbin-or-bin-usrbin

Tested:
```
$ find /tmp/phosphor-led-manager/ | grep libexec
/tmp/phosphor-led-manager/usr/local/libexec
/tmp/phosphor-led-manager/usr/local/libexec/phosphor-led-manager
/tmp/phosphor-led-manager/usr/local/libexec/phosphor-led-manager/phosphor-ledmanager
/tmp/phosphor-led-manager/usr/local/libexec/phosphor-led-manager/phosphor-fru-fault-monitor
$ find /tmp/phosphor-led-manager -type f | grep service
/tmp/phosphor-led-manager/usr/lib/systemd/system/obmc-fru-fault-monitor.service
/tmp/phosphor-led-manager/usr/lib/systemd/system/obmc-led-group-start@.service
/tmp/phosphor-led-manager/usr/lib/systemd/system/obmc-led-group-stop@.service
/tmp/phosphor-led-manager/usr/lib/systemd/system/xyz.openbmc_project.LED.GroupManager.service
```

Change-Id: Id34402c5d4ec40a6bb72f0a349c6dfb5ed1929e2
Signed-off-by: William de Abreu Pinho <williamdapinho@gmail.com>

show more ...