Add ThinkPad X270 coreboot port from Kat Inskip

Courtesy of Kat Inskip who ported this board.

Headphone output doesn't work at the moment, due to incorrect verb.
Intel VBT is also wrong. Both are taken from another board.

This will be amended later with the correct verb and VBT.

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/coreboot/x270_vfsp_16mb/target.cfg

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+tree="default"
+xarch="i386-elf"
+payload_seabios="y"
+payload_grub="y"
+payload_memtest="y"
+grub_scan_disk="nvme ahci"
+grubtree="xhci_nvme"
+vcfg="x270"
+build_depend="seabios/default grub/xhci_nvme memtest86plus"
+IFD_platform="sklkbl"
+
+# full ME (only deguard) used, so we don't want to do releases yet.
+# we only want to do releases of roms with a neutered ME
+
+release="n"