bare-metal-host-monitor: Add dbus configurations

Currently, the dbus service name, object, and property are all
hard-coded, but we need to be able to configure these dbus details for
different platforms. This commit introduces some meson build options for
this purpose. The default values can be overridden in a bbappend file.

Tested:
Set the bare metal flag /var/google/config-package/enable-bm.flag
Power cycled the machine, and confirmed that host-gpio-monitor@1.service
and host-gpio-monitor@2.service started.
Rebooted host 2, and confirmed this message showed up:
  <6> Post Complete state is InReset

Change-Id: I100ed2e450dbedf52565e0f35f50edba229ef800
Signed-off-by: John Wedig <johnwedig@google.com>
diff --git a/subprojects/bare-metal-host-monitor/meson_options.txt b/subprojects/bare-metal-host-monitor/meson_options.txt
new file mode 100644
index 0000000..43267b6
--- /dev/null
+++ b/subprojects/bare-metal-host-monitor/meson_options.txt
@@ -0,0 +1,36 @@
+option(
+  'host_monitor_service_name',
+  type: 'string',
+  value: 'xyz.openbmc_project.State.OperatingSystem{}',
+  description: 'Dbus service to monitor. Use {} in string if host number needs to be inserted'
+)
+option(
+  'host_monitor_object_path',
+  type: 'string',
+  value: '/xyz/openbmc_project/state/os',
+  description: 'Dbus object path to monitor. Use {} in string if host number needs to be inserted'
+)
+option(
+  'host_monitor_interface',
+  type: 'string',
+  value: 'xyz.openbmc_project.State.OperatingSystem.Status',
+  description: 'Dbus interface, where the monitored property is located.',
+)
+option(
+  'host_monitor_property',
+  type: 'string',
+  value: 'OperatingSystemState',
+  description: 'Dbus property to monitor',
+)
+option(
+  'host_monitor_host_in_reset_value',
+  type: 'string',
+  value: 'xyz.openbmc_project.State.OperatingSystem.Status.OSStatus.Inactive',
+  description: 'Dbus property value that indicates the host is in reset',
+)
+option(
+  'host_monitor_host_running_value',
+  type: 'string',
+  value: 'xyz.openbmc_project.State.OperatingSystem.Status.OSStatus.Standby',
+  description: 'Dbus property value that indicates the host OS is running',
+)