add 2 or more allocatable devices to a pod

[jxfruit]

as the issue #1181 Is this a BUG REPORT or FEATURE REQUEST?:

Uncomment only one, leave it on its own line:

/kind feature Currently, only one gpu device will be allocated, but in most scenarios, we hope two or more device on the same server or a few devices on servers can be allocated to a pod. Thank u!

[Thor-wl]

/kind feature