[gpu] introduce compute capability for nvidia accelerators (bug 13100)

https://intranet.grid5000.fr/bugzilla/show_bug.cgi?id=13100

data/grid5000/sites/grenoble/clusters/drac/nodes/drac-1.json

@@ -19,6 +19,7 @@
   "exotic": true,
   "gpu_devices": {
     "nvidia0": {
+      "compute_capability": "6.0",
       "cpu_affinity": 0,
       "device": "/dev/nvidia0",
       "memory": 17070817280,
@@ -28,6 +29,7 @@
       "vendor": "Nvidia"
     },
     "nvidia1": {
+      "compute_capability": "6.0",
       "cpu_affinity": 0,
       "device": "/dev/nvidia1",
       "memory": 17070817280,
@@ -37,6 +39,7 @@
       "vendor": "Nvidia"
     },
     "nvidia2": {
+      "compute_capability": "6.0",
       "cpu_affinity": 1,
       "device": "/dev/nvidia2",
       "memory": 17070817280,
@@ -46,6 +49,7 @@
       "vendor": "Nvidia"
     },
     "nvidia3": {
+      "compute_capability": "6.0",
       "cpu_affinity": 1,
       "device": "/dev/nvidia3",
       "memory": 17070817280,