host-reboot: move to PSM subdir

Per the project anti-patterns[1], scripts are suppose to be installed
in a package-named subdirectory within libexec.  Move appropriately
and update the service file.

[1]: https://github.com/openbmc/docs/blob/master/anti-patterns.md#background-4

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ie62e032707f374da4af20c38bbf358a8c442d690
diff --git a/meson.build b/meson.build
index 3a9f855..12daf35 100644
--- a/meson.build
+++ b/meson.build
@@ -276,7 +276,7 @@
 
 install_data('scripts/host-reboot',
         install_mode: 'rwxr-xr-x',
-        install_dir: get_option('libexecdir')
+        install_dir: get_option('libexecdir')/'phosphor-state-manager'
 )
 
 systemd = dependency('systemd')
diff --git a/service_files/phosphor-reboot-host@.service b/service_files/phosphor-reboot-host@.service
index a5cf9a1..49738c0 100644
--- a/service_files/phosphor-reboot-host@.service
+++ b/service_files/phosphor-reboot-host@.service
@@ -13,7 +13,7 @@
 # Since this is a part of the reboot target, call the startmin
 # target which does the minimum required to start the host if the reboot count
 # is not 0, otherwise it will quiesce the host.
-ExecStart=/usr/libexec/host-reboot %i
+ExecStart=/usr/libexec/phosphor-state-manager/host-reboot %i
 
 [Install]
 WantedBy=obmc-host-reboot@%i.target