Revert "Enforce 16bits SPDIF to bypass XBMC bug with 24bits samples"

This reverts commit 1fdf676a3d147d871c0a42b8fcfe5d77183c4c78.
Revert "Remove 24bits imx analog sound output for now"

This reverts commit b565d5fc613b00f4853fd7048db82f272f112de2.