util/lint: Omit more vendorcode from license header test

This is all code coming from the outside, so let's keep these files
untouched as much as possible.

A couple of files is added to the list by name because their license,
while free, can't be properly modelled in SPDX:

- lzmadecode is (LGPL OR CPL) WITH special-exception
- stack.c and start16 are some weird (but free) US Gov't license grant
- two XGI related files have "BSD except for Linux, where it's GPL"

Change-Id: I42dec503b9c427a66792d3fec99ca8df1a360e47
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41193
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

util/lint/lint-000-license-headers

@@ -8,10 +8,20 @@
 
 # regex list of files and directories to exclude from the search
 HEADER_EXCLUDED="\
+^src/commonlib/bsd/lz4.c.inc\$|\
+^src/cpu/x86/16bit/entry16.inc\$|\
+^src/device/oprom/x86emu/|\
+^src/device/oprom/include/x86emu/|\
+^src/device/oprom/yabel/|\
+^src/drivers/xgi/common/initdef.h\$|\
+^src/drivers/xgi/common/vstruct.h\$|\
 ^src/lib/gnat/|\
+^src/lib/lzmadecode.[ch]\$|\
+^src/lib/stack.c\$|\
 ^src/vendorcode/|\
 ^util/amdtools/example_input/|\
 ^util/cbfstool/lzma/|\
+^util/cbfstool/lz4/|\
 ^util/kconfig/|\
 Kconfig|\
 \<COPYING\>|\