northbridge/intel/pineview: Add native raminit

Does native ram init for Intel Atom D5xx 8086:a000 northbridge

Tested on Intel D510MO mainboard, board boots linux kernel

- Works fully with both dimms populated (2x2GB), memtest passes 100%
- Almost boots with only one dimm in one of the slots
  (suspect bad memory map with one dimm?)
- Reads garbage with only one dimm in other slot

Change-Id: Ibd22be2a959045e0a83aae2a3a0e877013f80711
Signed-off-by: Damien Zammit <damien@zamaudio.com>
Reviewed-on: https://review.coreboot.org/12501
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
3 files changed