move all sensor daemons to libexec

Per the organization anti-pattern, executables are expected to be
installed into libexec instead of bin[1].  Update service files and
meson to install there.

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

Change-Id: I1eb4003e94b83b09829d63346c2e16a3ff02a3e9
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/service_files/xyz.openbmc_project.adcsensor.service b/service_files/xyz.openbmc_project.adcsensor.service
index bc07f6e..399eea9 100644
--- a/service_files/xyz.openbmc_project.adcsensor.service
+++ b/service_files/xyz.openbmc_project.adcsensor.service
@@ -8,7 +8,7 @@
 [Service]
 Restart=always
 RestartSec=5
-ExecStart=/usr/bin/adcsensor
+ExecStart=/usr/libexec/dbus-sensors/adcsensor
 
 [Install]
 WantedBy=multi-user.target