Added || true to "ipmitool sel clear" so MAAS deployment can continue if that command fails
On Hinyari, "ipmitool sel clear" will exit with code 1 and output "Unable to clear SEL: Unspecified error",
which causes the entire deployment to fail.
Since this is not a critical step of the deployment, this should not happen. This change allows the deployment
to continue while still printing the error message to the console.
Consolidate GPU driver installation in late.sh and add late.sh call to curtin_userdata_grace
Currently, Grace systems do not have their GPU drivers automatically installed. This commit adds
that step for Grace systems.
Additionally, GPU driver installation will now only run on systems with an Nvidia GPU installed.
The appropriate open/non-open variant of the driver is selected based on the system specs.