drm/amd/pm: Adjust returns when power_profile_mode is not supported

This better aligns that the caller can make a mistake with the buffer
and -EINVAL should be returned, but if the hardware doesn't support
the feature it should be -EOPNOTSUPP.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Change-Id: I888153521084eb1c80f1b7dac8d6308df6d2a4d0