Revert "spl: imx6: Let spl_boot_device return USDHC1 or USDHC2"

Apologies to everyone whose board I broke by attempting to return
MMC1 or MMC2. I misunderstood how the MMC indexing worked.

This reverts commit 14d319b1856b86e593e01abd0a1e3c2d63b52a8a.

Signed-off-by: Adam Ford <aford173@gmail.com>
1 file changed