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/MPC8349ITX_defconfig b/configs/MPC8349ITX_defconfig
index 7c67d8c..9145ada 100644
--- a/configs/MPC8349ITX_defconfig
+++ b/configs/MPC8349ITX_defconfig
@@ -7,6 +7,7 @@
 CONFIG_BOOTDELAY=6
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="MPC8349E-mITX> "
+CONFIG_CMD_IDE=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_USB=y
 # CONFIG_CMD_SETEXPR is not set