Canyonlands SATA harddisk driver

This patch adds a SATA harddisk driver for the canyonlands.
This patch is kernel driver's porting.
This patch corresponded to not cmd_scsi but cmd_sata.
This patch divided an unused member with ifndef __U_BOOT__ in the structure.

[environment variable, boot script]
setenv bootargs root=/dev/sda7 rw
setenv bootargs ${bootargs} console=ttyS0,115200
ext2load sata 0:2 0x400000 /canyonlands/uImage
ext2load sata 0:2 0x800000 /canyonlands/canyonlands.dtb
fdt addr 0x800000 0x4000
bootm 0x400000 - 0x800000

If you drive SATA-2 disk on Canyonlands, you must change parts from
PI2PCIE212 to PI2PCIE2212 on U25. We confirmed to boot by using
following disks:

1.Vendor: Fujitsu	 Type: MHW2040BS
2.Vendor: Fujitsu	 Type: MHW2060BK
3.Vendor: HAGIWARA SYS-COM:HFD25S-032GT
4.Vendor: WesternDigital Type: WD3200BJKT (CONFIG_LBA48 required)
5.Vendor: WesternDigital Type: WD3200BEVT (CONFIG_LBA48 required)
6.Vendor: Hitachi	 Type: HTS543232L9A300 (CONFIG_LBA48 required)
7.Vendor: Seagate	 Type: ST31000333AS (CONFIG_LBA48 required)
8.Vendor: Transcend	 Type: TS32GSSD25S-M
9.Vendor: MTRON		 Type: MSD-SATA1525-016

Signed-off-by: Kazuaki Ichinohe <kazuichi at fsi.co.jp>