Kconfig: Add a CONFIG_IDE option

At present IDE support is controlled by CONFIG_CMD_IDE. Add a separate
CONFIG_IDE option so that IDE support can be enabled without requiring
the 'ide' command.

Update existing users and move the ide driver into drivers/block since
it should not be in common/.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/phytec/pcm030/pcm030.c b/board/phytec/pcm030/pcm030.c
index 983559e..bdd980d 100644
--- a/board/phytec/pcm030/pcm030.c
+++ b/board/phytec/pcm030/pcm030.c
@@ -176,7 +176,7 @@
 }
 #endif /* CONFIG_OF_BOARD_SETUP */
 
-#if defined(CONFIG_CMD_IDE) && defined(CONFIG_IDE_RESET)
+#if defined(CONFIG_IDE) && defined(CONFIG_IDE_RESET)
 
 #define GPIO_PSC2_4	0x02000000UL
 
@@ -206,4 +206,4 @@
 	} else
 		setbits_be32(&wu_gpio->dvo, GPIO_PSC2_4);
 }
-#endif /* defined(CONFIG_CMD_IDE) && defined(CONFIG_IDE_RESET) */
+#endif /* defined(CONFIG_IDE) && defined(CONFIG_IDE_RESET) */