AMD Northbridge LX: make sdram_* function prototypes non-static

In order to get rid of the bad #include "northbridge/amd/lx/raminit.c"
line we need to do some prepartion steps. This commit is one of them.

Change-Id: I33173660bbda8894e7672e41e1b994d254d7ae8a
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-on: http://review.coreboot.org/3362
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2 files changed