Make sure we have the latest buildx builder

Signed-off-by: Mikhail Malyshev <mike.malyshev@gmail.com>

Makefile.eve

@@ -47,16 +47,21 @@ help: Makefile
 	@echo "  clean: remove generated files"
 	@echo
 
+.PHONY: ensure-builder
+ensure-builder:
+	docker builder inspect eve-kernel-builder || docker builder create --name eve-kernel-builder --driver docker-container --bootstrap
+
 .PHONY: linuxkit
 linuxkit: $(LK)
 $(LK):
 	GOBIN=$(GOBIN) go install github.com/linuxkit/linuxkit/src/cmd/linuxkit@$(LINUXKIT_VERSION)
 
 KERNEL_OCI_FILE:=$(shell mktemp -u)-kernel.tar
 
-kernel-build-%: Makefile.eve linuxkit
+kernel-build-%: Makefile.eve linuxkit ensure-builder
 	@echo "Building kernel version $(BRANCH):$(VERSION)-$* with compiler $*"
 	docker buildx build \
+	--builder=eve-kernel-builder \
 	--build-arg="SOURCE_DATE_EPOCH=$(SOURCE_DATE_EPOCH)" \
 	--build-arg="KBUILD_BUILD_TIMESTAMP=$(KBUILD_BUILD_TIMESTAMP)" \
 	--build-arg="LOCALVERSION=$(VERSION)$(DIRTY)" \