[PATCH] Fix relocation problem with "new" get_dev() function

This patch enables the "new" get_dev() function for block devices
introduced by Grant Likely to be used on systems that still suffer
from the relocation problems (manual relocation neede because of
problems with linker script).

Hopefully we can resolve this relocation issue soon for all platform
so we don't need this additional code anymore.

Signed-off-by: Stefan Roese <sr@denx.de>