spd: Add module voltage for 1.8V

Add SSTL 1.8 V Interface Level as specified in
JEDEC_DDR2_SPD_Specification_ Rev1.3, page 10.

Change-Id: I0112a85f557826b629109e212dbbc752aeda305d
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/15202
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
1 file changed