build: remove unused DOCKER_STOCK_BIOS_DIR variable

build.sh

@@ -92,7 +92,6 @@ docker run --rm -it \
     -v "$PWD/$MODEL/build:$DOCKER_COREBOOT_DIR" \
     -v "$PWD/$MODEL:$DOCKER_SCRIPT_DIR" \
     -v "$PWD/common:$DOCKER_COMMON_SCRIPT_DIR" \
-    -v "$PWD/$MODEL/stock_bios:$DOCKER_STOCK_BIOS_DIR:ro" \
     -e COREBOOT_COMMIT="$COREBOOT_COMMIT" \
     -e COREBOOT_TAG="$COREBOOT_TAG" \
     -e COREBOOT_CONFIG="$COREBOOT_CONFIG" \

common/variables.sh

@@ -11,4 +11,3 @@ export DOCKER_ROOT_DIR="/home/coreboot"
 export DOCKER_SCRIPT_DIR="$DOCKER_ROOT_DIR/scripts"
 export DOCKER_COMMON_SCRIPT_DIR="$DOCKER_ROOT_DIR/common_scripts"
 export DOCKER_COREBOOT_DIR="$DOCKER_ROOT_DIR/cb_build"
-export DOCKER_STOCK_BIOS_DIR="$DOCKER_ROOT_DIR/stock_bios/"