Kconfig: Add CONFIG_SATA to enable SATA

At present CONFIG_CMD_SATA enables the 'sata' command which also brings
in SATA support. Some boards may wish to enable SATA without the command.
Add a separate CONFIG to permit this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/board/kosagi/novena/novena.c b/board/kosagi/novena/novena.c
index f6972c2..17c2b13 100644
--- a/board/kosagi/novena/novena.c
+++ b/board/kosagi/novena/novena.c
@@ -167,7 +167,7 @@
 	/* address of boot parameters */
 	gd->bd->bi_boot_params = PHYS_SDRAM + 0x100;
 
-#ifdef CONFIG_CMD_SATA
+#ifdef CONFIG_SATA
 	setup_sata();
 #endif