ata: ahci: Rename CONFIG_SATA_LPM_POLICY configuration item back

CONFIG_SATA_LPM_MOBILE_POLICY was renamed to CONFIG_SATA_LPM_POLICY in
commit 4dd4d3d ("ata: ahci: Rename CONFIG_SATA_LPM_MOBILE_POLICY
configuration item").

This can potentially cause problems as users would invisibly lose
configuration policy defaults when they built the new kernel. To
avoid such problems, switch back to the old name (even if it's wrong).

Suggested-by: Christoph Hellwig <hch@infradead.org>
Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

drivers/ata/Kconfig

@@ -115,14 +115,16 @@ config SATA_AHCI
 
 	  If unsure, say N.
 
-config SATA_LPM_POLICY
+config SATA_MOBILE_LPM_POLICY
 	int "Default SATA Link Power Management policy for low power chipsets"
 	range 0 4
 	default 0
 	depends on SATA_AHCI
 	help
 	  Select the Default SATA Link Power Management (LPM) policy to use
-	  for chipsets / "South Bridges" designated as supporting low power.
+	  for chipsets / "South Bridges" supporting low-power modes. Such
+	  chipsets are typically found on most laptops but desktops and
+	  servers now also widely use chipsets supporting low power modes.
 
 	  The value set has the following meanings:
 		0 => Keep firmware settings

drivers/ata/ahci.c

@@ -1595,7 +1595,7 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
 static void ahci_update_initial_lpm_policy(struct ata_port *ap,
 					   struct ahci_host_priv *hpriv)
 {
-	int policy = CONFIG_SATA_LPM_POLICY;
+	int policy = CONFIG_SATA_MOBILE_LPM_POLICY;
 
 
 	/* Ignore processing for chipsets that don't use policy */

drivers/ata/ahci.h

@@ -236,7 +236,7 @@ enum {
 	AHCI_HFLAG_NO_WRITE_TO_RO	= (1 << 24), /* don't write to read
 							only registers */
 	AHCI_HFLAG_USE_LPM_POLICY	= (1 << 25), /* chipset that should use
-							SATA_LPM_POLICY
+							SATA_MOBILE_LPM_POLICY
 							as default lpm_policy */
 	AHCI_HFLAG_SUSPEND_PHYS		= (1 << 26), /* handle PHYs during
 							suspend/resume */