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_64_defconfig b/configs/qemu-x86_64_defconfig
index 02e6af1..36d0185 100644
--- a/configs/qemu-x86_64_defconfig
+++ b/configs/qemu-x86_64_defconfig
@@ -32,6 +32,7 @@
 CONFIG_CMD_CPU=y
 # CONFIG_CMD_BOOTEFI_HELLO_COMPILE is not set
 # CONFIG_CMD_IMLS is not set
+CONFIG_CMD_IDE=y
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_SF=y
 CONFIG_CMD_SPI=y