payloads/depthcharge: enable LP_CHROMEOS in depthcharge

Fix standslone build failure after depthcharge patch
https://crrev.com/c/3461454 merge.

BUG=chrome-os-partner:226438207
TEST=Compiled brya and redrix in standalone mode.

Signed-off-by: Selma Bensaid <selma.bensaid@intel.com>
Change-Id: Ib2bb2ce42a314e05ef22ea7b8abc067d6361d511
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63240
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>
diff --git a/payloads/external/depthcharge/Makefile b/payloads/external/depthcharge/Makefile
index 23595e5..687e9f0 100644
--- a/payloads/external/depthcharge/Makefile
+++ b/payloads/external/depthcharge/Makefile
@@ -68,6 +68,8 @@
 		false)
 	echo $(DEPTHCHARGE_LIBPAYLOAD_MSG)
 	cp $(libpayload_config) $(libpayload_dir)/.config
+	(grep -q '^\s*CONFIG_LP_CHROMEOS=' $(libpayload_dir)/.config) || \
+		(echo "CONFIG_LP_CHROMEOS=y" >> $(libpayload_dir)/.config)
 	$(MAKE) -C $(libpayload_dir) olddefconfig
 	$(MAKE) -C $(libpayload_dir)
 	$(MAKE) -C $(libpayload_dir) install DESTDIR=$(libpayload_install_dir)