drivers/ddr/fsl: Dual-license DDR driver

drivers/ddr/fsl: Dual-license DDR driver

To make this driver easier to be reused, dual-license DDR driver.

Signed-off-by: York Sun <[email protected]>
CC: Simon Glass <[email protected]>
CC: Tom Rini <[email protected]>
CC: Heinrich Schuchardt <[email protected]>
CC: Thomas Schaefer <[email protected]>
CC: Masahiro Yamada <[email protected]>
CC: Robert P. J. Day <[email protected]>
CC: Alexander Merkle <[email protected]>
CC: Joakim Tjernlund <[email protected]>
CC: Curt Brune <[email protected]>
CC: Valentin Longchamp <[email protected]>
CC: Wolfgang Denk <[email protected]>
CC: Anatolij Gustschin <[email protected]>
CC: Ira W. Snyder <[email protected]>
CC: Marek Vasut <[email protected]>
CC: Kyle Moffett <[email protected]>
CC: Sebastien Carlier <[email protected]>
CC: Stefan Roese <[email protected]>
CC: Peter Tyser <[email protected]>
CC: Paul Gortmaker <[email protected]>
CC: Peter Tyser <[email protected]>
CC: Jean-Christophe PLAGNIOL-VILLARD <[email protected]>