ata: ahci_dm816: add compile test support

Add Kconfig dependendy on COMPILE_TEST to allow compile tests with
configs that do not enable ARCH_OMAP2PLUS.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index b100565..47b7b69 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -166,7 +166,7 @@
 
 config AHCI_DM816
 	tristate "DaVinci DM816 AHCI SATA support"
-	depends on ARCH_OMAP2PLUS
+	depends on ARCH_OMAP2PLUS || COMPILE_TEST
 	select SATA_HOST
 	help
 	  This option enables support for the DaVinci DM816 SoC's