nb/intel/sandybridge/raminit: Fix odt stretch
Move odt stretch into own function.
Apply workaround on SandyBridge C-stepping CPU only.
Apply odt stretch on all other CPU types.
Don't depend on empty DIMM detection, as in case one slot
is empty ref_card_offset is zero.
Change-Id: I4320f14e0522ec997b1f9f3b12ba2c2070ee8e9e
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/17616
Tested-by: build bot (Jenkins)
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>