boot/beaglev-ddrinit: update to include upstream fixes

Update commit ID to include recent upstream fixes:

- Fix I and D cache synchronization issue (2e2f6faaf105)
- Add carriage return to correct menu formatting (2f6ea51dbb51)
- Add copyright info (7d3413d2ffd9)
- Expand the limit on the size of uboot when update it (623888127a0e)

Signed-off-by: Drew Fustini <drew@beagleboard.org>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>