mb/google/hatch/romstage_spd_smbus.c: Fix missing DIMM issue

Since `commit 0ee9b14c09c` the SPD array is set to NULL if no
DIMM is present. This causes failure due to an unconditional use
of `blk.spd_array[i]`, : i={0,1}.

This validates the spd_array is non-NULL before use otherwise it
sets the DIMM as not present.


Puff fails boot with the following log:

```
 ...
SPD: banks 16, ranks 2, rows 16, columns 10, density 8192 Mb
SPD: device width 8 bits, bus width 64 bits
SPD: module size is 16384 MB (per channel)
ASSERTION ERROR: file 'src/soc/intel/cannonlake/cnl_memcfg_init.c', line 47
```

BUG=b:155220125
BRANCH=none
TEST=none

Change-Id: I5f47c849344951d53fa8c67e779b7c46d632d124
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40820
Reviewed-by: Jamie Chen <jamie.chen@intel.com>
Reviewed-by: Sam McNally <sammc@google.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Daniel Kurtz <djkurtz@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions