boot/beaglev-ddrlnit: new package

boot/beaglev-ddrlnit: new package

This commit adds a package for the DDR initialization code used on the
BeagleV platform.

The typo in the package name is upstream's typo, and we just keep it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[yann.morin.1998@free.fr:
  - upstream name is beaglev_ddrlnit, not *init (keep their typo)
  - rename package and variables accordingly
  - the referenced commit is no longer the HEAD of said branch
  - add a hash file
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>