mb/google/auron/var/lulu: Uniformise dual-channel handling

Lulu is the only variant that does not disable channel 1 in pei_data
when the SPD index indicates it is unused. For consistency with the
other variants that use SPD files, disable channel 1 explicitly.

Change-Id: I8c613c5d90075495d2f76d33abf15d74ac63c125
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55802
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/auron/variants/lulu/spd/spd.c

@@ -35,5 +35,7 @@ void mainboard_fill_spd_data(struct pei_data *pei_data)
 	if (!((spd_index == 0b0000) || (spd_index == 0b0011) ||
 	    (spd_index == 0b1010))) {
 		memcpy(pei_data->spd_data[1][0], pei_data->spd_data[0][0], SPD_LEN);
+	} else {
+		pei_data->dimm_channel1_disabled = 3;
 	}
 }