Convert CONFIG_CMD_IDE to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_IDE

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/qemu-x86_defconfig b/configs/qemu-x86_defconfig
index 73ee7b6..b648326 100644
--- a/configs/qemu-x86_defconfig
+++ b/configs/qemu-x86_defconfig
@@ -13,6 +13,7 @@
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_CPU=y
 # CONFIG_CMD_IMLS is not set
+CONFIG_CMD_IDE=y
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_PART=y
 CONFIG_CMD_SF=y