express: Update defconfig

Change-Id: I77851ea83fb8e95ecd0b75715119f4027af8f212
Revert "board: express: Increase ION_QSECOM size"

This reverts commit 4cf1e208689a8364c79ada1ed83be2e631d031da.
Revert "board: express: Add ION ADSP heap"

This reverts commit 0e32bbd07e67b03a9ad15c330a45206547fd5fb7.