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/include/configs/lsxl.h b/include/configs/lsxl.h
index d2c2101..43e4a32 100644
--- a/include/configs/lsxl.h
+++ b/include/configs/lsxl.h
@@ -145,7 +145,7 @@
 #undef CONFIG_RESET_PHY_R
 #endif /* CONFIG_CMD_NET */
 
-#ifdef CONFIG_CMD_IDE
+#ifdef CONFIG_IDE
 #undef CONFIG_IDE_LED
 #undef CONFIG_SYS_IDE_MAXBUS
 #define CONFIG_SYS_IDE_MAXBUS		1