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/drivers/pcmcia/marubun_pcmcia.c b/drivers/pcmcia/marubun_pcmcia.c
index afd6df6..739d754 100644
--- a/drivers/pcmcia/marubun_pcmcia.c
+++ b/drivers/pcmcia/marubun_pcmcia.c
@@ -17,7 +17,7 @@
 #define	CONFIG_PCMCIA
 #endif
 
-#if defined(CONFIG_CMD_IDE)
+#if defined(CONFIG_IDE)
 #define	CONFIG_PCMCIA
 #endif