dm: Rename disk uclass to ahci

This started as 'ahci' and was renamed to 'disk' during code review. But it
seems that this is too generic. Now that we have a 'blk' uclass, we can use
that as the generic piece, and revert to ahci for this.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/block/Kconfig

@@ -9,10 +9,9 @@ config BLK
 	  be partitioned into several areas, called 'partitions' in U-Boot.
 	  A filesystem can be placed in each partition.
 
-config DISK
-	bool "Support disk controllers with driver model"
+config AHCI
+	bool "Support SATA controllers with driver model"
 	depends on DM
-	default y if DM
 	help
 	  This enables a uclass for disk controllers in U-Boot. Various driver
 	  types can use this, such as AHCI/SATA. It does not provide any standard

drivers/block/Makefile

@@ -7,7 +7,7 @@
 
 obj-$(CONFIG_BLK) += blk-uclass.o
 
-obj-$(CONFIG_DISK) += disk-uclass.o
+obj-$(CONFIG_AHCI) += ahci-uclass.o
 obj-$(CONFIG_SCSI_AHCI) += ahci.o
 obj-$(CONFIG_DWC_AHSATA) += dwc_ahsata.o
 obj-$(CONFIG_FSL_SATA) += fsl_sata.o

drivers/block/ahci-uclass.c

@@ -8,7 +8,7 @@
 #include <common.h>
 #include <dm.h>
 
-UCLASS_DRIVER(disk) = {
-	.id		= UCLASS_DISK,
-	.name		= "disk",
+UCLASS_DRIVER(ahci) = {
+	.id		= UCLASS_AHCI,
+	.name		= "ahci",
 };