km/common: change ubicopy variable

Instead having a hard coded value for "cramfsaddr" after compile time,
we change it to take the variable "cramfsaddr" for the ubicopy variable.
This makes sure that ubicopy uses the right address, even when
the value for "cramfsaddr" has changed.

CC: Valentin Longchamp <valentin.longchamp@hitachi-powergrids.com>
CC: Heiko Schocher <hs@denx.de>
CC: Tom Rini <trini@konsulko.com>
Signed-off-by: Holger Brunck <holger.brunck@hitachi-powergrids.com>
Reviewed-by: Heiko Schocher <hs@denx.de>