ata: mvebu: move mvebu sata driver to drivers/ata directory

Currently mvebu sata driver is in arch/arm/mach_mvebu directory, this
patch moves it to drivers/ata directory with renaming "sata.c" to
"ahci_mvebu.c" which is aligned to Linux.
New ahci driver's kconfig option is added as AHCI_MVEBU which selects
SCSI_AHCI and is based on AHCI.

Signed-off-by: Ken Ma <make@marvell.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 86ec628..36e1748 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -99,4 +99,14 @@
 	help
 	  Enable this driver to support the SIL3114 SATA controllers.
 
+config AHCI_MVEBU
+	bool "Marvell EBU AHCI SATA support"
+	depends on ARCH_MVEBU
+	depends on AHCI
+	select SCSI_AHCI
+	help
+	  This option enables support for the Marvell EBU SoC's
+	  onboard AHCI SATA.
+
+	  If unsure, say N.
 endmenu