mb/starlabs/labtop: Add LabTop Mk III

Tested using MrChromeBox's `uefipayload_202107` branch:
* Windows 10
* Ubuntu 20.04
* MX Linux 19.4
* Manjaro 21

No known issues.

https://starlabs.systems/pages/labtop-mk-iii-specification

Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Change-Id: Ia52566e06f50c0abcfb657044538db8e92564c36
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58538
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Ben McMillen <ben@starlabs.systems>
diff --git a/src/mainboard/starlabs/labtop/variants/kbl/romstage.c b/src/mainboard/starlabs/labtop/variants/kbl/romstage.c
new file mode 100644
index 0000000..098f753
--- /dev/null
+++ b/src/mainboard/starlabs/labtop/variants/kbl/romstage.c
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <option.h>
+#include <soc/romstage.h>
+#include <spd_bin.h>
+#include <string.h>
+#include <types.h>
+
+void mainboard_memory_init_params(FSPM_UPD *mupd)
+{
+	FSP_M_CONFIG *mem_cfg = &mupd->FspmConfig;
+	const u16 rcomp_resistor[] = {121, 81, 100};
+	const u16 rcomp_target[] = {100, 40, 20, 20, 26};
+
+	memcpy(&mem_cfg->RcompResistor, rcomp_resistor, sizeof(rcomp_resistor));
+	memcpy(&mem_cfg->RcompTarget, rcomp_target, sizeof(rcomp_target));
+
+	mem_cfg->MemorySpdPtr00 = spd_cbfs_map(6);
+	mem_cfg->MemorySpdPtr10 = mem_cfg->MemorySpdPtr00;
+	mem_cfg->MemorySpdDataLen = CONFIG_DIMM_SPD_SIZE;
+
+	const uint8_t ht = get_uint_option("hyper_threading",
+		mupd->FspmConfig.HyperThreading);
+	mupd->FspmConfig.HyperThreading = ht;
+}