Create GPU Inventory device

adds Item.accelerator interface for GPU devices

Tested
```
root@gb200nvl-obmc:~# busctl introspect xyz.openbmc_project.GpuSensor /xyz/openbmc_project/inventory/NVIDIA_GB200_GPU_0
NAME                                           TYPE      SIGNATURE RESULT/VALUE FLAGS
org.freedesktop.DBus.Introspectable            interface -         -            -
.Introspect                                    method    -         s            -
org.freedesktop.DBus.Peer                      interface -         -            -
.GetMachineId                                  method    -         s            -
.Ping                                          method    -         -            -
org.freedesktop.DBus.Properties                interface -         -            -
.Get                                           method    ss        v            -
.GetAll                                        method    s         a{sv}        -
.Set                                           method    ssv       -            -
.PropertiesChanged                             signal    sa{sv}as  -            -
xyz.openbmc_project.Inventory.Item.Accelerator interface -         -            -
.Type                                          property  s         "GPU"        emits-change
```

Change-Id: I20434529860cb37889e63651bbcd97cadfa9d54e
Signed-off-by: Rohit PAI <ropai@nvidia.com>
diff --git a/src/nvidia-gpu/meson.build b/src/nvidia-gpu/meson.build
index 39ce871..5c7f958 100644
--- a/src/nvidia-gpu/meson.build
+++ b/src/nvidia-gpu/meson.build
@@ -10,6 +10,7 @@
     'NvidiaGpuThresholds.cpp',
     'NvidiaGpuVoltageSensor.cpp',
     'OcpMctpVdm.cpp',
+    'Inventory.cpp',
 )
 
 gpusensor_include_dir = include_directories('.', is_system: true)