ACPI: OSI: Remove Linux-Lenovo-NV-HDMI-Audio _OSI string

This string was introduced because drivers for NVIDIA hardware
didn't handle HDMI properly.

This was fixed by commit b516ea58 ("PCI: Enable NVIDIA HDA
controllers"), so vendors shouldn't be using this string to modify
ASL any more.

Suggested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>