ata: pata_at91 only works on sam9

The smc driver used by pata_at91 is at91sam9 specific, so building
this driver on another at91 platform results in this error:

ERROR: "sam9_smc_configure" [drivers/ata/pata_at91.ko] undefined!
ERROR: "sam9_smc_write_mode" [drivers/ata/pata_at91.ko] undefined!
ERROR: "sam9_smc_read_mode" [drivers/ata/pata_at91.ko] undefined!

This patch changes the Kconfig dependency to ensure it always works.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: linux-ide@vger.kernel.org
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>

drivers/ata/Kconfig

@@ -815,7 +815,7 @@ config PATA_AT32
 
 config PATA_AT91
 	tristate "PATA support for AT91SAM9260"
-	depends on ARM && ARCH_AT91
+	depends on ARM && SOC_AT91SAM9
 	help
 	  This option enables support for IDE devices on the Atmel AT91SAM9260 SoC.