ahci: Add Intel Comet Lake PCH-U PCI ID

Add Intel Comet Lake PCH-U PCI ID to the list of supported controllers.

Set default SATA LPM so the SoC can enter S0ix.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>