Replace CONFIG_MMC_BOUNCE_BUFFER with CONFIG_BOUNCE_BUFFER in configs

Commits 6dc71c8d "MMC: MXS: Toggle the generic bounce buffer on the
boards" and 49a627f8 "MMC: Remove the MMC bounce buffer" replaced
CONFIG_MMC_BOUNCE_BUFFER with CONFIG_BOUNCE_BUFFER, but missed
converting a few boards over to the new option. Fix this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andy Fleming <afleming@freescale.com>