uboot-imx

ums: use get_device() not find_mmc_device();

get_device() is a generic routine that will support any type of block
device. Use this instead of the type-specific find_mmc_device(), for
future flexibility.

Cc: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>