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/cmd/Kconfig b/cmd/Kconfig
index 2c89a77..1268e38 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -486,6 +486,7 @@
 
 config CMD_IDE
 	bool "ide - Support for IDE drivers"
+	select IDE
 	help
 	  Provides an 'ide' command which allows accessing the IDE drive,
 	  reseting the IDE interface, printing the partition table and