Dynamically set GPU application clock speed using nvidia-smi output

[brannondorsey]

Issue #, if available:

Fixes #954 and supersedes #1097 if merged.

Description of changes:

Avoid maintaining a static mapping of GPU names to maximum clock speed values as suggested in https://github.com/awslabs/amazon-eks-ami/pull/1097#issuecomment-1311892158.

Pros:

• Automatically set application clock speeds when new GPU instance types are added, without having to maintain a static list of clock speeds (avoiding issues like #954).

Cons:

• Possibly fragile to changes in the nvidia-smi --query --xml-format output format

Testing Done

These changes have been tested manually on an EKS node with a recent AMI.