Avoid drive spin down during a warm boot.

Call the BMIC Flush Cache command (0xc2) to indicate the reason for the
flush cache (shutdown, hibernate, suspend, or restart).

Link: https://lore.kernel.org/r/164375208810.440833.11254644025650871435.stgit@brunhilda.pdev.netReviewed-by: NMike McGowen <mike.mcgowen@microchip.com>
Reviewed-by: NScott Benesh <scott.benesh@microchip.com>
Reviewed-by: NScott Teel <scott.teel@microchip.com>
Signed-off-by: NSagar Biradar <sagar.biradar@microchip.com>
Signed-off-by: NDon Brace <don.brace@microchip.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>