buffet: Add base GCD command definition .json file

Added gcd.json file to contain all standard command definitions
for all GCD-based device types, along with the commands' standard
parameters. Right now the file has a simple defintion for
base.reboot command.

Also moved buffet.conf to the new etc sub-directory to indicate
the target locataion for the file to be installed under on the
actual device image. As well as org.chromium.Buffet.conf moved
from buffet/dbus tp buffet/etc/dbus-1.

BUG=chromium:394913
TEST=build_image & cros deploy it onto a link device
CQ-DEPEND=CL:208779

Change-Id: I54da10bf6733685f9e2f0c945e7b7257f2904557
Reviewed-on: https://chromium-review.googlesource.com/208794
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>

buffet/etc/buffet/gcd.json

diff --git a/buffet/etc/buffet/gcd.json b/buffet/etc/buffet/gcd.json
new file mode 100644
index 0000000..b488802
--- /dev/null
+++ b/buffet/etc/buffet/gcd.json
@@ -0,0 +1,8 @@
+{
+  "base": {
+    "reboot": {
+      "parameters": {
+      }
+    }
+  }
+}

buffet/etc/dbus-1/org.chromium.Buffet.conf

diff --git a/buffet/dbus/org.chromium.Buffet.conf b/buffet/etc/dbus-1/org.chromium.Buffet.conf
similarity index 100%
rename from buffet/dbus/org.chromium.Buffet.conf
rename to buffet/etc/dbus-1/org.chromium.Buffet.conf

buffet/etc/init/buffet.conf

diff --git a/buffet/buffet.conf b/buffet/etc/init/buffet.conf
similarity index 100%
rename from buffet/buffet.conf
rename to buffet/etc/init/buffet.conf