EDAC: Add missing MEM_LRDDR4 entry in edac_mem_types[]

The edac_mem_types[] array misses a MEM_LRDDR4 entry, which leads to
NULL pointer dereference when accessed via sysfs or such.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180810141426.8918-1-tiwai@suse.de
Fixes: 1e8096bb

 ("EDAC: Add LRDDR4 DRAM type")
Signed-off-by: Borislav Petkov <bp@suse.de>