smbios: Add Type19

Implement type 19 by accumulating the DRAM dimm size found in cbmem's
CBMEM_ID_MEMINFO structure. This seems common on x86 where the
address space always starts at 0.

At least EDK2 uses this table in the UI and shows 0 MB DRAM if not
present.

Change-Id: Idee8b8cd0b155e14d62d4c12893ff01878ef3f1c
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43672
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Christian Walter <christian.walter@9elements.com>

src/include/smbios.h

@@ -828,6 +828,19 @@ struct smbios_type17 {
 	u8 eos[2];
 } __packed;
 
+struct smbios_type19 {
+	u8 type;
+	u8 length;
+	u16 handle;
+	u32 starting_address;
+	u32 ending_address;
+	u16 memory_array_handle;
+	u8 partition_width;
+	u64 extended_starting_address;
+	u64 extended_ending_address;
+	u8 eos[2];
+} __packed;
+
 struct smbios_type32 {
 	u8 type;
 	u8 length;